The Court of Justice of the European Union: Structure, Jurisdiction, and Judicial Authority

The Court of Justice of the European Union: Structure, Jurisdiction, and Judicial Authority

The Court of Justice of the European Union occupies a central position in the constitutional structure of the European Union. Its principal responsibility is to ensure that EU law is interpreted and applied consistently across all Member States and that the institutions of the Union and national authorities respect the legal obligations established by the Treaties.

The Union is not merely a political or economic association. It is a legal order in which treaties, regulations, directives, decisions, and judicial principles create rights and obligations for institutions, Member States, businesses, and individuals. Such a legal system requires an independent judicial authority capable of resolving disputes, interpreting common rules, reviewing institutional action, and maintaining the uniform application of Union law.

The Court of Justice of the European Union (CJEU) fulfils this function through a judicial structure consisting of two courts: the Court of Justice and the General Court. Although these courts form part of the same EU institution, they have distinct jurisdictions and procedural responsibilities. The Court of Justice principally deals with preliminary references from national courts, infringement proceedings against Member States, certain direct actions against EU institutions, and appeals on points of law. The General Court hears many direct actions brought by individuals, companies, and organisations against EU institutions, bodies, offices, and agencies, as well as other categories of cases assigned to it by the Treaties and the Statute.

The Court’s authority is particularly important because EU law operates within national legal systems. National courts apply EU law in disputes involving individuals and public authorities, but questions concerning the meaning or validity of Union law may require an authoritative interpretation from the CJEU. Through this relationship between European and national courts, the Union maintains a common legal framework without replacing the national judicial systems of its Member States.

The CJEU is therefore not simply an appellate court above national courts. It is the judicial institution responsible for safeguarding the autonomy, consistency, and effectiveness of EU law within the constitutional framework established by the Treaties.

1. Constitutional Foundations and Legal Status

The constitutional basis of the Court of Justice of the European Union is established principally by Article 19 of the Treaty on European Union (TEU), Articles 251–281 of the Treaty on the Functioning of the European Union (TFEU), and Protocol No 3 on the Statute of the Court of Justice of the European Union.

Article 19(1) TEU provides that the CJEU includes the Court of Justice and the General Court and that it must ensure that the law is observed in the interpretation and application of the Treaties. This provision establishes the institution’s fundamental constitutional responsibility.

Article 19(2) TEU addresses the composition of the courts, while Article 19(3) identifies their principal jurisdictional functions. These include:

• Ruling on actions brought by Member States, institutions, or other parties where the Treaties confer jurisdiction;
• Giving preliminary rulings, at the request of national courts and tribunals, on the interpretation of Union law or the validity of acts adopted by EU institutions;
• Ruling in other cases provided for by the Treaties.

The Court’s jurisdiction is not unlimited. It is based on the principle of conferral: the CJEU may exercise judicial authority only within the jurisdiction assigned to it by the Treaties and the applicable legal instruments. It cannot intervene in every dispute involving a Member State, nor can it act as a general court of appeal against decisions of national judges.

Article 19 TEU also contains a broader constitutional requirement. Member States must provide remedies sufficient to ensure effective legal protection in the fields covered by Union law. This obligation connects the jurisdiction of the CJEU with the responsibility of national courts to provide judicial protection when individuals rely on rights arising from EU law.

The Court’s institutional status is consequently twofold. It is an EU institution with authority over the legality of Union action, but it is also the central judicial authority within a legal system that depends substantially on national courts for the application and enforcement of European rules. EUR-Lex+2

2. Historical Development of the Court

The judicial institution now known as the Court of Justice of the European Union was established in 1952, following the creation of the European Coal and Steel Community. Its original purpose was to ensure that the Community’s founding treaty and the legal measures adopted under it were interpreted and applied consistently.

As European integration expanded, the Court’s role developed beyond the resolution of disputes between institutions and Member States. It became an important force in defining the constitutional principles of the emerging European legal order.

Two early judgments were particularly influential.

In Van Gend en Loos v Nederlandse Administratie der Belastingen (Case 26/62), the Court established the principle of direct effect. It held that certain provisions of Community law could create rights for individuals which national courts were required to protect. The judgment transformed the relationship between Community law and individuals by recognising that European rules were not simply obligations between states.

In Costa v ENEL (Case 6/64), the Court developed the principle of primacy of Community law. It held that the legal system created by the Community could not be overridden by conflicting national legislation without undermining the uniformity and effectiveness of Community law.

These decisions were central to the development of the Union’s legal order. They established that European law could operate directly within national legal systems and that national authorities could not treat conflicting domestic legislation as automatically prevailing over applicable Community law.

The growth in the number and complexity of cases eventually required institutional reform. The General Court was established in 1988 and began operating in 1989, initially as the Court of First Instance. Its creation allowed the judicial system to distribute a growing volume of direct actions, particularly disputes involving businesses and individuals.

The Treaty of Lisbon, which entered into force in 2009, consolidated the institution’s position within the EU framework and confirmed the terminology now used: the Court of Justice of the European Union as the institution, comprising the Court of Justice and the General Court.

Further reforms have addressed workload, procedural efficiency, and the allocation of jurisdiction. An important recent development took effect on 1 October 2024, when the General Court received jurisdiction over preliminary references in six specified subject areas. This reform was designed to distribute the workload more effectively while preserving the Court of Justice’s responsibility for questions involving fundamental principles and the consistency of EU law. European Union+2

3. Institutional Structure: The Court of Justice and the General Court

The CJEU is one institution, but its two constituent courts perform different judicial functions. Understanding this distinction is essential because the expression “Court of Justice” is often used informally to describe the entire institution, even though it refers legally to one of its two courts.

3.1 The Court of Justice

The Court of Justice is the senior judicial court within the institution. It is composed of one Judge from each Member State, giving it 27 Judges, and is assisted by 11 Advocates General.

Its principal responsibilities include:

• Preliminary rulings on the interpretation and validity of EU law, subject to the jurisdiction transferred to the General Court;
• Infringement proceedings against Member States;
• Certain actions for annulment and failure to act;
• Disputes between EU institutions where the Treaties confer jurisdiction;
• Appeals on points of law against decisions of the General Court.

The Court of Justice is particularly important in maintaining the uniform interpretation of EU law. Its judgments establish authoritative interpretations of Treaty provisions, regulations, directives, and other Union legal instruments.

It does not ordinarily reconsider the facts of a national dispute referred to it by a national court. Instead, it interprets the relevant provisions of EU law so that the national court can apply that interpretation when deciding the underlying proceedings.

3.2 The General Court

The General Court is the other constituent court of the CJEU. It has 54 Judges, two from each Member State.

Its principal function is to hear many direct actions brought by individuals, companies, and organisations against decisions or acts of EU institutions, bodies, offices, and agencies. It also hears specified actions brought by Member States and other disputes assigned to it by the Treaties and the Statute.

Its jurisdiction includes, among other matters:

• Actions for annulment;
• Actions for failure to act;
• Actions for damages arising from non-contractual liability of the Union;
• Certain disputes involving EU staff;
• Contractual disputes where the relevant agreement confers jurisdiction on the Union courts;
• Preliminary references in six specified subject areas.

The General Court therefore plays a substantial role in reviewing the legality of EU administrative and regulatory action. Its work is particularly significant in competition law, State aid, trade measures, intellectual property, restrictive measures, and disputes involving EU agencies.

Its decisions may generally be appealed to the Court of Justice on points of law, subject to the applicable procedural rules. The appeal system allows the Court of Justice to correct errors of law and preserve consistency in the interpretation of EU law.

3.3 The distinction between the two courts

The distinction is not simply that one court is superior and the other inferior. Their jurisdictions are organised to distribute different categories of cases and ensure that the judicial system can operate efficiently.

The General Court acts as the principal first-instance court for many direct actions brought by private parties. The Court of Justice retains responsibility for major constitutional questions, preliminary references outside the transferred categories, infringement proceedings, and appeals on points of law.

Both courts form part of the same EU institution and contribute to the protection of the Union’s legal order. curia+2

4. Judges: Appointment, Independence, and Qualifications

The independence of the judiciary is essential to the legitimacy of the CJEU. Its Judges must be able to interpret and apply EU law without political instructions or interference from national governments, EU institutions, or private parties.

Under Article 19(2) TEU, the Court of Justice consists of one Judge from each Member State, while the General Court consists of at least one Judge from each Member State. The present composition of the General Court provides for two Judges from each Member State.

Judges are appointed by common accord of the governments of the Member States for a term of six years. Their terms are renewable.

Candidates must be persons whose independence is beyond doubt and who possess the qualifications required for appointment to the highest judicial offices in their respective countries, or who are jurists of recognised competence.

Before appointment, candidates are assessed by a panel established under Article 255 TFEU. The panel gives an opinion on their suitability to perform the duties of Judge or Advocate General. This assessment is intended to strengthen the quality and independence of judicial appointments.

The appointment process reflects the Member States’ role in constituting the Union’s judicial institutions, while the qualification and independence requirements protect the judicial character of the office.

Judges take an oath to perform their duties impartially and conscientiously and to preserve the secrecy of the Court’s deliberations. They are not representatives of their Member States. Although each Member State nominates a Judge, that Judge must decide cases independently and in accordance with EU law.

This distinction is fundamental. The national origin of a Judge does not create a right for a Member State to influence the outcome of proceedings or demand that its Judge defend national interests.

5. Advocates General and Their Function

The Court of Justice is assisted by Advocates General, whose role is established by Article 252 TFEU.

There are currently 11 Advocates General. They are appointed under the same general framework of independence and professional qualification that applies to Judges.

An Advocate General is not a prosecutor and does not represent a party to the proceedings. The function is to assist the Court by delivering an independent, impartial, and reasoned Opinion in cases requiring such participation.

The Opinion examines the legal questions raised by the proceedings, relevant Treaty provisions, existing case law, and the arguments submitted by the parties. It may propose an interpretation of EU law or explain how the Court should resolve a difficult legal issue.

The Court is not bound by the Advocate General’s Opinion. It may follow the reasoning, adopt only part of it, or reach a different conclusion. The judgment remains the authoritative decision of the Court.

Opinions can nevertheless be highly influential. They provide detailed legal analysis and may clarify competing interpretations of EU law, especially in cases involving constitutional principles, institutional powers, or novel legal questions.

The General Court does not have a permanent body of Advocates General equivalent to that of the Court of Justice. Under the relevant procedural framework, a Judge of the General Court may perform an Advocate General’s function in specified circumstances. EUR-Lex+1

6. Chambers and the Organisation of Judicial Work

The Court of Justice does not ordinarily sit with all 27 Judges in every case. Its work is organised through chambers, allowing cases to be allocated according to their nature, complexity, and legal importance.

Under Article 251 TFEU and the Statute, the Court of Justice may sit in chambers of three or five Judges, in a Grand Chamber, or, in specified circumstances, as a full Court.

The Grand Chamber normally consists of 15 Judges and hears cases of particular importance or complexity, including cases where a Member State or EU institution that is a party requests its involvement under the applicable rules.

The full Court is reserved for exceptional circumstances provided for by the Statute, including certain proceedings involving the removal of an EU Ombudsman or a member of the European Commission where the Treaties and Statute prescribe that formation.

The General Court also operates through chambers, generally composed of three or five Judges. It may sit in a Grand Chamber or other formations where the procedural rules and importance of the case justify doing so. It also has specialised chambers dealing with particular categories of preliminary references transferred to it.

The use of chambers is not merely an administrative convenience. It allows the judicial institution to manage a substantial caseload while ensuring that significant questions receive consideration by an appropriately constituted formation.

Judgments are delivered in the name of the court concerned. The deliberations of the Judges are confidential, and judgments express the collective judicial decision rather than publishing individual dissenting opinions. This differs from the practice of several national supreme courts, where separate concurring or dissenting judgments may be published.

7. Jurisdiction of the Court of Justice of the European Union

The jurisdiction of the CJEU is defined by the Treaties and the Statute. It is not a general jurisdiction over every dispute connected with Europe or every legal disagreement involving a Member State. Its authority is limited to matters falling within the Union legal order and the specific judicial powers conferred upon it.

The principal categories of jurisdiction include preliminary rulings, infringement proceedings, actions for annulment, actions for failure to act, claims for damages, contractual disputes, and appeals from the General Court.

These procedures perform different constitutional functions. Some protect the uniform interpretation of EU law, others enforce the obligations of Member States, and others ensure that EU institutions remain within the limits of their legal authority.

7.1 Preliminary rulings under Article 267 TFEU

The preliminary ruling procedure is one of the most important mechanisms in the EU judicial system. It establishes a relationship between the CJEU and national courts, allowing the latter to obtain an authoritative interpretation of EU law when necessary to decide a case.

Under Article 267 TFEU, the Court of Justice has jurisdiction to give preliminary rulings concerning:

• The interpretation of the Treaties;
• The validity and interpretation of acts adopted by EU institutions, bodies, offices, or agencies.

A national court may refer a question where it considers that an answer is necessary to enable it to give judgment. A national court against whose decisions there is no judicial remedy under national law must, in principle, refer a necessary question of EU law to the CJEU.

The procedure is not an appeal against a national judgment. The CJEU does not take over the national proceedings, determine the underlying facts, or ordinarily decide the dispute between the parties. It answers the question of EU law, and the national court then applies that answer to the case before it.

For example, a national court may be dealing with a dispute concerning a consumer contract, employment rights, taxation, environmental protection, or the recognition of professional qualifications. If the outcome depends on the interpretation of an EU directive or regulation, the national court may refer a question to the CJEU.

The preliminary ruling procedure serves two principal purposes. First, it prevents different national courts from developing conflicting interpretations of the same EU provision. Second, it allows EU law to be applied effectively through national judicial systems, which handle the great majority of disputes involving individuals and businesses.

Courts required to refer questions

Article 267 distinguishes between courts that may refer questions and courts whose decisions are not subject to judicial remedy under national law.

A lower national court generally has discretion to refer a question where it considers a ruling necessary. A court of final instance is generally required to refer a relevant question of interpretation, subject to the exceptions developed in the Court’s case law.

In CILFIT (Case 283/81), the Court explained circumstances in which a court of last instance may be relieved of the obligation to refer. These include situations where the question is irrelevant to the outcome, where the Court has already interpreted the provision in question, or where the correct interpretation is so clear that there is no reasonable doubt, taking account of the particular characteristics of EU law.

The doctrine commonly associated with the final exception is known as acte clair. It does not mean that national courts may avoid references whenever they personally consider an interpretation straightforward. The assessment must take account of the autonomous terminology of EU law, its context, and the need for uniform interpretation across the Union.

Preliminary rulings on validity

The preliminary ruling procedure also allows national courts to raise questions concerning the validity of EU acts.

A particularly important principle was established in Foto-Frost v Hauptzollamt Lübeck-Ost (Case 314/85). The Court held that national courts may reject arguments that an EU act is invalid, but they cannot themselves declare an EU act invalid. The authority to declare an EU act invalid belongs to the EU Courts.

This rule protects the uniformity of EU law. If national courts could independently invalidate Union legislation, the same EU measure might be valid in one Member State and invalid in another. Centralised judicial authority prevents this fragmentation.

Transfer of certain preliminary references to the General Court

A significant reform entered into force on 1 October 2024. Under Article 256(3) TFEU and the amended Statute, the General Court now has jurisdiction to hear preliminary references falling exclusively within six specified subject areas:

1. The common system of value added tax;
2. Excise duties;
3. The Customs Code;
4. The tariff classification of goods under the Combined Nomenclature;
5. Compensation and assistance to passengers in cases of denied boarding, delay, or cancellation of transport services;
6. The system for greenhouse gas emission allowance trading.

The transfer is intended to distribute the increasing workload of preliminary references between the two courts. It does not remove the preliminary ruling procedure from the Court of Justice or make the General Court the general preliminary ruling court.

The Court of Justice retains jurisdiction where a reference raises independent questions concerning primary EU law, public international law, general principles of EU law, or the Charter of Fundamental Rights. It also retains the ability to deal with questions of principle affecting the unity or consistency of Union law under the applicable statutory arrangements.

The national court continues to receive an authoritative answer and remains responsible for deciding the underlying dispute. The transfer changes which EU court examines certain questions, not the fundamental relationship between national courts and the Union judiciary. curia+2

7.2 Infringement proceedings against Member States

The CJEU also exercises jurisdiction over proceedings concerning a Member State’s failure to fulfil obligations under EU law.

The principal legal basis is Articles 258–260 TFEU. These provisions establish a mechanism through which compliance with EU obligations can be enforced judicially.

Article 258 TFEU allows the European Commission to bring proceedings against a Member State that it considers to have failed to fulfil an obligation under the Treaties. Such a failure may involve a national law incompatible with EU law, incorrect implementation of a directive, failure to implement a directive within the prescribed period, or an administrative practice that violates Union obligations.

The procedure normally begins with a pre-litigation stage. The Commission investigates the alleged breach and may send a letter of formal notice, giving the Member State an opportunity to submit observations. If the Commission considers that the breach remains unresolved, it may issue a reasoned opinion identifying the alleged failure and setting a period for compliance.

If the Member State does not comply within the prescribed period, the Commission may refer the matter to the Court of Justice.

The Court then determines whether the Member State has failed to fulfil its obligations. It does not ordinarily decide the validity of the national legislation under domestic constitutional law. Instead, it examines whether the state’s conduct is compatible with its obligations under EU law.

Article 259 TFEU provides a separate route through which one Member State may bring proceedings against another. Before bringing the matter before the Court, the Member State must refer it to the Commission for an opinion. Although legally available, this procedure is less frequently used than Commission-led infringement proceedings.

A judgment finding an infringement is binding on the Member State concerned. Under Article 260(1) TFEU, the state must take the necessary measures to comply with the judgment.

If the Member State fails to comply, the Commission may bring further proceedings under Article 260(2) TFEU and request the imposition of a lump sum or penalty payment. The Court determines whether a financial sanction is appropriate and fixes its amount.

Article 260(3) TFEU provides an additional mechanism for certain failures to notify measures transposing a directive adopted under a legislative procedure. In these circumstances, the Commission may propose financial sanctions in the initial infringement proceedings, subject to the Treaty conditions.

Infringement proceedings are therefore an important mechanism for maintaining the uniform application of EU law. They ensure that Member States cannot disregard their Treaty obligations without the possibility of judicial enforcement.

7.3 Actions for annulment under Article 263 TFEU

An action for annulment is a procedure through which the legality of an EU act can be challenged before the Union Courts.

Article 263 TFEU allows the CJEU to review the legality of legislative acts and certain acts of the European Parliament, the European Council, the Council, the Commission, the European Central Bank, and other Union bodies, offices, or agencies intended to produce legal effects vis-à-vis third parties.

The grounds for annulment include:

• Lack of competence;
• Infringement of an essential procedural requirement;
• Infringement of the Treaties or any rule of law relating to their application;
• Misuse of powers.

These grounds protect the principle that EU institutions must act within the authority conferred upon them and comply with the procedures and substantive requirements established by EU law.

The allocation of jurisdiction between the two courts is important. Many actions brought by individuals and companies are heard at first instance by the General Court. The Court of Justice retains jurisdiction over specified actions brought by Member States and EU institutions, including certain challenges to acts of the European Parliament, the European Council, and the Council.

An action for annulment is subject to strict time limits. Under Article 263 TFEU, proceedings must generally be instituted within two months of publication of the act, its notification to the applicant, or, in the absence of either, the date on which it came to the applicant’s knowledge.

Private applicants face additional standing requirements. They may challenge acts addressed to them, acts of direct and individual concern to them, and certain regulatory acts that are of direct concern to them and do not entail implementing measures.

The requirement of individual concern is particularly demanding. In Plaumann v Commission (Case 25/62), the Court developed the test under which a person must be affected by reason of attributes peculiar to them or circumstances distinguishing them from all other persons in a manner comparable to the addressee of the act.

The action for annulment is an essential safeguard against unlawful institutional action. It ensures that the political and administrative authority of the Union remains subject to judicial control.

7.4 Actions for failure to act under Article 265 TFEU

An action for failure to act addresses situations in which an EU institution, body, office, or agency has unlawfully failed to take action required by the Treaties.

It differs from an action for annulment because the challenge concerns institutional inaction rather than an existing measure.

Before proceedings can normally be brought, the institution concerned must have been formally called upon to act. If it fails to define its position within the applicable period, the applicant may bring an action before the Union Courts, subject to the conditions of Article 265 TFEU.

The procedure is not a general means of compelling an institution to adopt a particular policy or legislation. It concerns failures to act where a legal obligation to define a position exists.

The action therefore protects the principle that institutional powers and responsibilities cannot be exercised through arbitrary inaction where the Treaties impose a duty to act.

7.5 Actions for damages and non-contractual liability

The Union may incur liability where its institutions or servants cause damage in the performance of their duties.

Article 268 TFEU gives the Union Courts jurisdiction over disputes relating to compensation for damage under Article 340(2) and (3) TFEU.

Article 340 establishes the principle that the Union must make good damage caused by its institutions or servants in the performance of their duties, in accordance with the general principles common to the laws of the Member States.

An action for damages is distinct from an action for annulment. A claimant seeking compensation must establish the relevant conditions for Union liability. These generally include unlawful conduct attributable to the institution, the existence of actual damage, and a sufficiently direct causal link between the conduct and the damage.

The General Court hears many such claims at first instance. The procedure provides a means of obtaining compensation where the requirements of Union liability are satisfied, rather than merely seeking the annulment of an institutional act.

7.6 Contractual disputes

The Union Courts may also have jurisdiction over contractual disputes involving the European Union where the relevant contract contains an arbitration clause conferring jurisdiction under Article 272 TFEU.

This jurisdiction is not automatic for every contract involving a public body or an EU institution. It depends on the contractual and Treaty conditions.

Where jurisdiction is validly conferred, the Union Courts may determine the dispute in accordance with the law governing the contract and the relevant procedural rules.

8. Appeals and the Relationship Between the Two Courts

The Court of Justice exercises appellate jurisdiction over certain decisions of the General Court.

Under Article 256 TFEU, appeals may generally be brought on points of law. This means that an appeal is not an opportunity to conduct a complete retrial of the facts or simply to ask the Court of Justice to reassess the evidence.

The appeal may concern errors in the interpretation or application of EU law, procedural irregularities affecting the interests of the appellant, or other legal errors within the applicable grounds of appeal.

If the appeal is well founded, the Court of Justice may set aside the General Court’s decision. Where the state of the proceedings permits, it may give final judgment itself. Otherwise, it may refer the case back to the General Court, which is then bound by the legal principles established in the appeal judgment.

Special rules apply to appeals against certain decisions of the General Court where it has reviewed decisions of independent boards of appeal within EU agencies. In specified categories, an appeal may proceed only where the Court of Justice allows it because the issue is significant for the unity, consistency, or development of EU law.

The system also provides for exceptional review of certain preliminary rulings delivered by the General Court. Under Article 256(3) TFEU and the Statute, the Court of Justice may review such a decision where there is a serious risk that the unity or consistency of Union law would be affected.

The appellate structure therefore serves two related purposes: correcting errors of law and protecting the coherent development of the EU legal system.

9. Judicial Procedure Before the CJEU

Proceedings before the CJEU are governed by the Statute and the Rules of Procedure of the respective courts. Although procedures vary according to the type of action, they generally involve written submissions and, where appropriate, an oral hearing.

9.1 The written phase

The written phase allows the parties to present their legal arguments and supporting materials.

In direct actions, the applicant submits an application setting out the claims, grounds, and requested relief. The defendant responds, and further written submissions may be permitted under the applicable procedural rules.

In preliminary ruling proceedings, the national court sends the reference and relevant information about the underlying dispute. The parties to the national proceedings, Member States, and certain EU institutions may submit written observations.

The written phase is important because it identifies the legal issues that the Court must address and allows interested participants to contribute arguments concerning the interpretation or validity of EU law.

9.2 The oral phase

An oral hearing may be held where the Court considers it appropriate. The parties or their representatives present arguments and respond to questions from the Judges.

Hearings are generally public, subject to the applicable procedural exceptions. The oral phase allows the Court to examine difficult legal questions directly and clarify points that may not have been sufficiently addressed in the written submissions.

9.3 The Advocate General’s Opinion

Where an Advocate General is assigned to a case, the Opinion is generally delivered after the oral phase. It provides independent legal analysis and may propose a particular approach to resolving the dispute.

Not every case requires an Advocate General’s Opinion. The Court may determine that a case raises no new point of law requiring one, in accordance with the Statute and procedural rules.

9.4 Deliberation and judgment

After the relevant procedural stages, the Judges deliberate in private and reach a decision. The judgment is delivered in open court and becomes authoritative in accordance with the applicable procedural rules.

The judgments of the CJEU are binding within their respective legal contexts. A preliminary ruling binds the referring national court as to the interpretation or validity of the relevant EU provision. Judgments in direct actions have the legal effects prescribed by the Treaties.

The Court’s judgments are published and made accessible through the institution’s case-law database and EUR-Lex, allowing national courts, institutions, legal practitioners, academics, and the public to examine the development of EU law.

10. The Authority and Legal Effects of CJEU Judgments

The judicial authority of the CJEU derives not only from its power to decide individual disputes but also from the effects its judgments have throughout the Union’s legal system.

Its judgments contribute to the interpretation of EU law, establish principles governing the relationship between Union and national law, and determine whether institutional or national action complies with Treaty obligations.

10.1 Binding effect of preliminary rulings

A preliminary ruling provides an authoritative interpretation of EU law or determines the validity of a Union act. The referring national court must apply the ruling when deciding the underlying dispute.

The significance of a preliminary ruling extends beyond the individual proceedings. Other national courts dealing with materially similar questions must take account of the interpretation established by the CJEU. This promotes consistency and prevents the development of incompatible national interpretations.

A preliminary ruling does not ordinarily annul national legislation. Rather, it establishes the meaning or validity of the relevant EU provision, enabling the national court to determine the consequences for the national proceedings.

10.2 Effects of judgments in infringement proceedings

A judgment under Article 258 TFEU establishes whether a Member State has failed to fulfil its obligations under EU law.

The Member State must take the measures necessary to comply. The judgment does not necessarily invalidate national legislation automatically through a domestic legislative procedure, but the state is under a binding obligation to remedy the infringement.

If the state fails to comply, further proceedings and financial sanctions may follow under Article 260 TFEU.

10.3 Effects of judgments in actions for annulment

Where an action for annulment is successful, Article 264 TFEU provides that the contested act is declared void.

The judgment may have effects extending beyond the immediate applicant because the annulled measure is removed from the Union legal order. However, the Court may, where appropriate, state which effects of the annulled act must be regarded as definitive.

This power is particularly important where immediate annulment could create legal uncertainty or disrupt existing legal relationships.

10.4 Judicial authority and national implementation

The CJEU does not generally execute its judgments through national enforcement officers or take over the administration of national legal systems. Compliance is achieved through the obligations imposed on Member States and institutions, the application of EU law by national courts, and the enforcement mechanisms established by the Treaties.

This structure reflects the decentralised nature of the Union legal order. The CJEU provides authoritative judicial interpretation, while national courts and authorities remain responsible for applying EU law in their respective jurisdictions.

11. Fundamental Principles Developed Through the Court’s Case Law

The CJEU has played a decisive role in developing the constitutional principles of EU law. Although the Treaties provide the formal foundation of the Union’s legal order, their interpretation through judicial decisions has clarified how European law operates in practice.

Several principles are particularly important.

11.1 Direct effect

In Van Gend en Loos (Case 26/62), the Court established that certain provisions of Community law could create individual rights enforceable before national courts.

The principle of direct effect allows individuals to rely on sufficiently clear, precise, and unconditional provisions of EU law before national judicial authorities, subject to the specific requirements applicable to the type of provision concerned.

The judgment changed the understanding of European integration by recognising individuals as participants in the legal order, rather than merely beneficiaries of obligations between states.

11.2 Primacy of EU law

In Costa v ENEL (Case 6/64), the Court established that EU law takes precedence over conflicting national law within the scope of its application.

The principle of primacy ensures that Member States cannot undermine the effectiveness of Union law by adopting domestic measures that contradict applicable EU obligations.

In Simmenthal (Case 106/77), the Court further clarified that national courts must give effect to applicable EU law and set aside conflicting national provisions, without waiting for those provisions to be formally repealed or declared unconstitutional under domestic procedures.

The principle is central to the uniform application of EU law, although its relationship with national constitutional identity and the constitutional doctrines of Member States has remained an important subject of legal debate.

11.3 State liability

In Francovich and Bonifaci v Italy (Joined Cases C-6/90 and C-9/90), the Court recognised that Member States may be required to compensate individuals for damage caused by breaches of EU law attributable to the state.

The principle was further developed in Brasserie du Pêcheur and Factortame III (Joined Cases C-46/93 and C-48/93).

State liability strengthens the effectiveness of EU law by providing a remedy where an infringement causes loss to individuals and the relevant conditions for compensation are satisfied.

11.4 Effective judicial protection

The Court has recognised effective judicial protection as a fundamental requirement of the EU legal order. This principle is reflected in Article 19 TEU and Article 47 of the Charter of Fundamental Rights of the European Union.

It requires that individuals have access to effective remedies when rights derived from EU law are affected. National procedural rules must respect the principles of equivalence and effectiveness: they must not treat EU-based claims less favourably than comparable domestic claims or make the exercise of EU rights practically impossible or excessively difficult.

11.5 Institutional legality and judicial review

In Les Verts v European Parliament (Case 294/83), the Court described the European Community as a Community based on the rule of law, in which neither Member States nor institutions can avoid judicial review of the conformity of their acts with the Treaties.

The judgment helped establish the constitutional importance of judicial review in the Union’s institutional system.

Together, these principles demonstrate that the CJEU does more than resolve disputes. Through the interpretation of Treaty provisions and the development of general principles, it has shaped the constitutional operation of the European Union.

12. The Relationship Between the CJEU and National Courts

The relationship between the CJEU and national courts is one of the defining characteristics of the EU judicial system.

National courts are responsible for deciding the vast majority of disputes involving EU law. They interpret and apply Union legislation, protect rights arising under EU law, and ensure that national authorities comply with applicable European obligations.

The CJEU does not replace these courts. Instead, it provides authoritative interpretations and ensures that questions of EU law are resolved consistently across Member States.

The preliminary ruling procedure is the principal mechanism through which this judicial cooperation operates.

This relationship is sometimes described as a judicial dialogue. A national court identifies a question concerning EU law and refers it to the CJEU. The CJEU answers the legal question, after which the national court resumes the proceedings and applies the ruling.

The process combines centralised interpretation with decentralised application. The Union has one authoritative judicial interpreter of EU law, but its rules are implemented through the national judicial systems.

This arrangement is particularly important because national legal systems differ in procedural structure, judicial organisation, and substantive legal traditions. Without a common mechanism of interpretation, the same European provision might acquire different meanings in different Member States.

The relationship also places responsibilities on national courts. They must provide effective judicial protection, respect the primacy of applicable EU law, and refer questions where the conditions of Article 267 TFEU require it.

The CJEU’s authority is therefore exercised through cooperation rather than through a complete hierarchy of European courts replacing national judicial institutions.

13. Limits of the Court’s Jurisdiction

The CJEU has extensive judicial authority, but that authority remains subject to important legal and constitutional limits.

First, it cannot exercise jurisdiction merely because a dispute has political significance or involves a Member State. A legal basis must exist in the Treaties or other applicable instruments.

Second, the Court is not a general appellate court for national litigation. It does not reconsider every factual finding or legal conclusion reached by national courts. Its preliminary ruling jurisdiction concerns questions of EU law, leaving the final decision in the underlying dispute to the national court.

Third, individuals cannot bring every alleged breach of EU law directly before the CJEU. Direct actions are subject to strict jurisdictional and admissibility rules. In particular, actions brought by individuals against EU institutions will generally begin before the General Court and must satisfy the standing requirements of Article 263 TFEU where an action for annulment is involved.

Fourth, the CJEU does not ordinarily have jurisdiction to interpret national law as such. It may explain the requirements of EU law and assess whether national measures are compatible with those requirements, but the interpretation and application of national law remain principally matters for national courts.

Fifth, the Court must respect the division of competences established by the Treaties. It cannot create general legislative powers for the Union or substitute judicial preferences for political choices that the Treaties leave to the EU institutions or Member States.

These limits are essential to the constitutional legitimacy of the judicial institution. The CJEU safeguards the Union’s legal order, but it does so within a framework of conferred powers, procedural rules, and institutional balance.

14. The CJEU and the Charter of Fundamental Rights

The Charter of Fundamental Rights of the European Union has strengthened the constitutional significance of the CJEU.

Since the entry into force of the Treaty of Lisbon, the Charter has the same legal value as the Treaties under Article 6(1) TEU. It protects a broad range of civil, political, economic, and social rights, including dignity, freedom, equality, solidarity, citizens’ rights, and justice.

The CJEU interprets and applies the Charter within the scope of EU law. It reviews Union acts for compliance with fundamental rights and ensures that Member States respect the Charter when they are implementing or otherwise acting within the scope of EU law.

Article 51 of the Charter defines its field of application. The Charter does not extend the competences of the Union or create a general EU jurisdiction over all national human rights questions.

The Court’s fundamental-rights jurisdiction is therefore closely connected to the scope of Union law. Where a national measure falls within that scope, the Charter may provide a standard against which the measure is assessed.

Article 47, concerning the right to an effective remedy and a fair trial, is particularly important. It reinforces the requirement that judicial protection must be available when rights guaranteed by EU law are violated.

The CJEU also operates within a wider European human rights environment. The European Convention on Human Rights is a separate international treaty administered through the Council of Europe, and the European Court of Human Rights is a distinct judicial institution. The CJEU and the European Court of Human Rights must not be confused, even though their work may concern related fundamental-rights questions.

15. Contemporary Challenges and the Future of the EU Judiciary

The CJEU faces several structural and constitutional challenges arising from the continuing development of European integration.

One major challenge is the increasing volume and complexity of litigation. EU law now covers a wide range of policy fields, including digital regulation, competition, environmental protection, financial services, data protection, migration, intellectual property, and consumer rights. These areas generate increasingly complex disputes requiring specialised legal knowledge.

The transfer of certain preliminary references to the General Court from October 2024 represents one response to this workload. Its effectiveness will depend on the ability of the two courts to manage their respective responsibilities while maintaining consistent interpretations of EU law.

A second challenge concerns the relationship between EU law and national constitutional systems. The principles of primacy and uniform application are essential to the operation of the Union, but national constitutional courts have sometimes raised questions about the limits of EU authority, constitutional identity, and the protection of fundamental rights.

These debates concern the constitutional structure of the Union rather than simply disagreements about individual judgments. They require the institutions and national courts to maintain judicial dialogue while respecting the legal obligations established by the Treaties.

A third challenge concerns the protection of judicial independence and the rule of law within Member States. Article 19 TEU requires Member States to provide effective judicial protection in fields covered by Union law. The CJEU has consequently developed an important body of case law concerning the independence of national courts, judicial appointments, disciplinary arrangements, and the conditions necessary for effective judicial review.

A fourth challenge arises from technological and regulatory developments. Questions concerning artificial intelligence, digital platforms, automated decision-making, cybersecurity, and cross-border data processing increasingly require the interpretation of complex EU legal instruments. The Court must ensure that existing principles remain applicable while addressing new forms of economic and administrative activity.

Finally, the CJEU must preserve public confidence in its independence, impartiality, and reasoning. Its authority depends not on political representation but on the quality of its judicial work, the consistency of its legal interpretation, and its ability to apply the Treaties without favouring individual governments or institutions.

The future development of the Court will therefore involve balancing judicial independence, procedural efficiency, legal certainty, and the constitutional diversity of the Member States.

16. Key Takeaways

1. The Court of Justice of the European Union is the judicial institution responsible for ensuring that EU law is interpreted and applied consistently across the Member States.

2. The CJEU consists of two courts: the Court of Justice and the General Court.

3. The Court of Justice has 27 Judges and 11 Advocates General. The General Court has 54 Judges.

4. Judges are appointed by common accord of the Member State governments for renewable six-year terms and must satisfy strict requirements of independence and professional qualification.

5. The Court of Justice principally hears preliminary references, infringement proceedings, certain direct actions, and appeals on points of law.

6. The General Court hears many direct actions brought by individuals, companies, and organisations against EU institutions and other Union bodies.

7. Article 267 TFEU establishes the preliminary ruling procedure, enabling national courts to obtain authoritative interpretations of EU law.

8. Since 1 October 2024, the General Court has jurisdiction over preliminary references in six specified subject areas, subject to the exceptions established by the Statute.

9. Articles 258–260 TFEU establish infringement proceedings through which Member States may be held responsible for failing to fulfil their EU obligations.

10. Article 263 TFEU provides for judicial review of the legality of EU acts, while Article 265 addresses unlawful failures by EU institutions to act.

11. The Court’s case law has developed fundamental principles including direct effect, primacy, state liability, and effective judicial protection.

12. The CJEU works in cooperation with national courts rather than replacing them. National courts remain responsible for deciding the underlying disputes in preliminary ruling proceedings.

13. The Court is bound by the jurisdiction and procedures established by the Treaties and must respect the principle of conferral and institutional balance.

17. Frequently Asked Questions

1. What is the Court of Justice of the European Union?

The Court of Justice of the European Union is the judicial institution of the EU. It ensures that EU law is interpreted and applied consistently and that Member States and EU institutions comply with their legal obligations.

2. What is the difference between the Court of Justice and the Court of Justice of the European Union?

The Court of Justice of the European Union is the name of the entire judicial institution. It consists of two courts: the Court of Justice and the General Court. The Court of Justice is one constituent court, not the name of the entire institution.

3. Where is the CJEU located?

The CJEU is located in Luxembourg, where its judicial proceedings and institutional administration are conducted.

4. How many Judges serve at the CJEU?

The Court of Justice has 27 Judges, one from each Member State. The General Court has 54 Judges, two from each Member State.

5. What is the role of an Advocate General?

An Advocate General provides an independent and impartial legal Opinion in cases requiring such involvement. The Opinion assists the Court but does not bind it. The Court delivers the authoritative judgment.

6. Can individuals bring cases directly before the CJEU?

Individuals and companies may bring certain direct actions before the General Court, particularly challenges to EU institutional decisions or claims for damages. However, strict jurisdictional, standing, and procedural requirements apply. Individuals cannot generally bring an infringement action directly against a Member State before the Court of Justice.

7. What is a preliminary ruling?

A preliminary ruling is a decision of the CJEU answering a question referred by a national court concerning the interpretation of EU law or the validity of an EU act. The national court uses the answer to decide the underlying dispute.

8. Are national courts required to refer questions to the CJEU?

National courts may refer questions where they consider an answer necessary. Courts against whose decisions there is no judicial remedy under national law must generally refer necessary questions of EU law, subject to the exceptions established by the Court’s case law.

9. Can the CJEU invalidate national legislation?

The CJEU does not ordinarily annul national legislation through an action for annulment. It can interpret EU law and determine whether national measures are compatible with it. National courts must then apply EU law and the relevant principles of primacy and effective judicial protection.

10. Can the CJEU declare an EU act invalid?

Yes. The EU Courts may declare EU acts void through an action for annulment under Article 263 TFEU. In preliminary ruling proceedings, the Court of Justice also has authority to determine the validity of EU acts. National courts cannot themselves declare an EU act invalid.

11. What happens when a Member State fails to comply with EU law?

The Commission may initiate infringement proceedings under Article 258 TFEU. If the Court finds an infringement, the Member State must take the necessary measures to comply. Continued non-compliance may result in financial sanctions under Article 260 TFEU.

12. Are CJEU judgments binding on Member States?

Yes. Their legal effects depend on the type of proceedings. Judgments in infringement cases bind the Member State concerned, while preliminary rulings provide authoritative interpretations that the referring court must apply and that other national courts must take into account in similar cases.

13. What is the difference between the CJEU and the European Court of Human Rights?

The CJEU is an institution of the European Union and interprets and applies EU law. The European Court of Human Rights is a judicial institution of the Council of Europe and supervises compliance with the European Convention on Human Rights. They belong to different legal systems and have different jurisdictions.

14. What is the principle of primacy of EU law?

The principle of primacy means that applicable EU law takes precedence over conflicting national law. It was developed through the Court’s case law, particularly Costa v ENEL and Simmenthal, and is essential to the uniform application of Union law.

15. Why is the CJEU important to European integration?

The CJEU ensures that common European rules have a consistent legal meaning and are respected by institutions and Member States. Through its judgments, it has developed the principles that make EU law an autonomous and effective legal order.

18. Conclusion

The Court of Justice of the European Union is indispensable to the constitutional functioning of the Union. Its authority ensures that European integration operates within a common legal framework in which institutions, governments, and individuals are subject to enforceable legal rules.

Its institutional structure reflects the complexity of the Union’s judicial responsibilities. The Court of Justice protects the uniform interpretation of EU law, resolves infringement proceedings, determines important institutional disputes, and hears appeals on points of law. The General Court provides judicial review in a broad range of disputes involving individuals, businesses, Member States, and EU institutions.

The preliminary ruling procedure connects these European courts with national judicial systems, allowing EU law to be interpreted centrally while being applied through national courts. This cooperation is one of the defining characteristics of the Union’s legal order.

The Court’s constitutional contribution is equally significant. Through its case law, it has developed principles such as direct effect, primacy, state liability, and effective judicial protection. These principles have transformed the relationship between the Union, its Member States, and individuals.

Ultimately, the authority of the CJEU rests on the principle that European integration must remain governed by law. Political institutions may establish priorities, adopt legislation, and formulate common policies, but their actions must remain within the limits of the Treaties. The Court provides the judicial safeguards necessary to maintain that constitutional order.

19. Primary Legal Sources and Further Reading

Treaty provisions

• Article 19 TEU – The Court of Justice of the European Union
• Article 251 TFEU – Composition and formations of the Court of Justice
• Article 252 TFEU – Advocates General
• Article 253 TFEU – Appointment and status of Judges and Advocates General
• Article 256 TFEU – Jurisdiction of the General Court
• Article 258 TFEU – Infringement proceedings brought by the Commission
• Article 259 TFEU – Proceedings brought by a Member State
• Article 260 TFEU – Compliance with judgments and financial sanctions
• Article 263 TFEU – Actions for annulment
• Article 265 TFEU – Actions for failure to act
• Article 267 TFEU – Preliminary rulings
• Article 268 TFEU – Jurisdiction in damages actions
• Article 340 TFEU – Non-contractual liability of the Union

Official institutional resources

• Court of Justice of the European Union – Official website
• The Court of Justice – Composition, functions, and jurisdiction
• The General Court – Composition and jurisdiction
• Court of Justice of the European Union – Case-law database
• EUR-Lex – EU case law
• European Parliament – Competences of the Court of Justice of the European Union

Selected landmark judgments

• Van Gend en Loos v Nederlandse Administratie der Belastingen, Case 26/62, EU:C:1963:1.
• Costa v ENEL, Case 6/64, EU:C:1964:66.
• Plaumann v Commission, Case 25/62, EU:C:1963:17.
• Simmenthal, Case 106/77, EU:C:1978:49.
• Foto-Frost v Hauptzollamt Lübeck-Ost, Case 314/85, EU:C:1987:452.
• CILFIT and Others, Case 283/81, EU:C:1982:335.
• Francovich and Bonifaci v Italy, Joined Cases C-6/90 and C-9/90, EU:C:1991:428.
• Brasserie du Pêcheur and Factortame III, Joined Cases C-46/93 and C-48/93, EU:C:1996:79.
• Les Verts v European Parliament, Case 294/83, EU:C:1986:166.