← The hardest concepts in European Union law
In one breath
The Union may conclude international agreements not only where the Treaties expressly say so but also where this is necessary to achieve a Treaty objective, or where the matter is already covered by common rules that the agreement could affect. When the Union acquires such a power in an area, the Member States may lose their own right to commit themselves to third countries on that subject.
The picture
The steward and the outside contractor
An estate owner puts a steward in charge of the roads inside the estate. Nothing in his instructions says he may sign anything with the neighbouring estate. But suppose the roads cannot be kept in order unless he agrees with the neighbour about a shared boundary track. The authority to run the roads then carries with it the authority to make that agreement, because the job cannot otherwise be done.
Now suppose the steward has already laid down detailed rules for all traffic on the estate’s roads. The owner’s relatives may no longer cut their own deals with the neighbour about how traffic is to behave, because their deals might upset the steward’s rules. In EU law the first step is the rule that internal power can imply an external one; the second is that, once common rules exist, the Member States lose the freedom to act alone where they might affect those rules.
Where the picture stops working
A steward’s powers are a matter between him and one owner. The Union’s external powers are shared with the Member States in many fields, and some agreements are concluded by both together as “mixed” agreements. The picture also fails to show that treaty-making has its own procedure in the Treaties and that the Court of Justice may be asked in advance whether a planned agreement is compatible with the Treaties.
How it really works
- 1Know where the rule comes from. It began in the Court’s case law and is now reflected in the Treaty on the Functioning of the European Union (Articles 3(2) and 216). The idea is therefore both judge-made and codified.
- 2Start with express powers. Some Treaty articles directly empower the Union to conclude agreements, for example on trade or association.
- 3Look for an implied power. Where the Treaties give the Union an internal power, the Court has held that the authority to enter international commitments in the same field may follow, so that internal and external action go together.
- 4Ask whether common rules exist. When the Union has adopted common rules in an area, Member States may not enter into commitments with third countries that might affect those rules or alter their scope.
- 5Decide who signs. The result may be Union competence alone, Member State competence alone, or a mixed agreement signed by both.
Why people get it wrong
- Assuming the Union may do externally only what the Treaties list externally. The Court has not read the list as exhaustive.
- Thinking the Member States lose all treaty-making power. They retain it where the Union has no competence or has not made rules that an agreement could affect.
- Ignoring the timing. The Member States’ freedom shrinks as the Union’s internal rules develop, not before.
- Treating mixed agreements as a loophole. They reflect a division of competence, and the duty of cooperation applies.
- Confusing the Union’s legal personality with the powers it may use. Personality says the Union can hold rights and obligations; the Treaties and case law say in which areas.
A worked example
The facts are invented
Suppose the Union has adopted detailed common rules on the rest periods of lorry drivers on international routes. A Member State then wants to sign a bilateral treaty with a neighbouring non-member country setting its own rest periods for drivers crossing their border. Each term might look harmless alone, but together the treaty could cut across the Union’s common rules.
On the usual analysis, the Member State may not conclude it. Because the subject is already covered by common rules, the power to bind third countries on those matters now lies with the Union, and a separate national agreement could affect the rules or alter their scope. The Union would negotiate with the neighbour itself. Had no common rules existed, the answer would have been different, and the State could have acted subject to its other Union duties.
Try it
The Union has adopted detailed common rules on a subject. A Member State wishes to sign a treaty with a non-member country on the same subject. What is the usual position?
Landmark authorities
Read the sources themselves; this list is a starting point.
- Commission v Council (ERTA or AETR), Case 22/70, 1971
- Opinion 1/76 (Rhine Laying-up Fund), 1977
- Treaty on the Functioning of the European Union, Articles 3(2) and 216, exclusive and implied external competence
Where to go next
More hard concepts in European Union law
- Conferral of powers and the categories of competence (Institutional law)
- Subsidiarity and proportionality (Institutional law)
- Regulations, directives and decisions (Sources of law)
This page is an educational overview. It is not legal advice and not a substitute for the sources: the statute, the rule, the case itself. EU law is made by the Union’s institutions under powers that the Member States have conferred on it in the Treaties, and it is applied by national courts and the Court of Justice together. The national law of each Member State still governs most of private and criminal law. Each page says whether the idea comes from the Treaties, from regulations and directives, or from the Court of Justice’s case law. Each page states the usual formulation of the rule and names landmark decisions; check the primary sources, and the law of your own Member State, before relying on any rule.