← The hardest concepts in Australian law
In one breath
Chapter III of the Constitution gives the judicial power of the Commonwealth only to courts, and the Boilermakers principle adds the reverse: a federal court may exercise nothing but judicial power, apart from what is incidental to it. The result is a double wall that keeps courts out of the work of governing and keeps governing bodies out of the work of judging.
The picture
The kitchen and the dining room
A restaurant keeps two rooms apart. Only licensed chefs may cook in the kitchen, and the owner may not send in a waiter to prepare the meals, however busy the night. Equally, the chefs are not to be sent out to take orders, set the menu or haggle with suppliers. The kitchen is protected from outsiders and the chefs are protected from distraction, and diners trust the food because both rules hold.
The Constitution builds the same arrangement. Cooking is judicial power: deciding an existing dispute about legal rights by a binding ruling that applies the law to the facts. In the federal system only the High Court, other federal courts and authorised State courts may do it. Taking orders and setting menus is legislative and executive work, such as making rules for the future, and a federal court cannot be given it, because mixing the roles threatens the court’s independence and the public’s confidence that its decisions rest on the law alone.
Where the picture stops working
A kitchen has a door, but judicial power has no simple definition, and courts describe it by features such as a binding decision about rights, reached by a fair process. The walls are not perfectly clean either: a court may do things incidental to its judicial role, a judge may take on a role in a personal capacity if they consent, and a few exceptions such as military discipline have been accepted.
How it really works
- 1Place the rule. It is constitutional and federal, binding the Commonwealth Parliament and the federal courts. The States have no equivalent strict separation, although State courts receive a different protection.
- 2Ask whether the function is judicial power: a binding determination of an existing dispute about rights or liabilities, reached by applying law to facts. Adjudging and punishing criminal guilt is, as a general rule, exclusively judicial.
- 3If it is, ask who exercises it. Only a Chapter III court may. A minister, department or tribunal cannot be given power to make that kind of binding ruling.
- 4If the body is a federal court, ask whether the extra function is non-judicial. It cannot be given one unless it is incidental to the court’s judicial work, or a judge acts in a personal capacity with consent.
- 5State the consequence. A conferral that breaks either rule is invalid to that extent, and Parliament must redesign the scheme, for example by creating a body that only recommends.
Why people get it wrong
- Believing all three arms of government are strictly separate. Ministers sit in Parliament; the strict separation is of judicial power alone.
- Treating every body that holds a hearing as exercising judicial power. A tribunal that makes a fresh decision on the merits of an administrative decision does administrative work.
- Assuming the label settles it. Parliament cannot turn judicial power into something else by changing its name.
- Applying the principle to State courts in the same way. They are protected differently, and the Kable principle is narrower.
- Forgetting the incidental route. A court may do what is necessary to exercise its judicial power effectively.
A worked example
The facts are invented
Parliament creates the Standards Court, a federal court, and gives it two jobs: to decide whether companies have broken a product safety rule, and to decide each year which products the Minister should ban, with the Minister bound by its choice. The first job is judicial. The second is a policy decision that belongs to the executive, so conferring it on a federal court offends the Boilermakers principle and is invalid.
Change the facts: the Act lets the Minister’s department find that a company has broken the rule and impose a fine, with no court involved. That is judicial power exercised by a non-court, and it is invalid. The department may investigate and apply to a court, which then decides.
Try it
Parliament creates a federal court and gives it power to decide whether companies have broken a safety law, and also to decide as a matter of policy which products the Minister must ban. What is the likely problem?
Landmark authorities
Read the sources themselves; this list is a starting point.
- Huddart, Parker & Co Pty Ltd v Moorehead, (1909) 8 CLR 330
- R v Kirby; Ex parte Boilermakers’ Society of Australia, (1956) 94 CLR 254
- Attorney-General (Cth) v The Queen, (1957) 95 CLR 529
- Chu Kheng Lim v Minister for Immigration, Local Government and Ethnic Affairs, (1992) 176 CLR 1
Where to go next
Courses
Dictionary
More hard concepts in Australia law
- Section 109: when Commonwealth and State laws clash (Constitutional law)
- The implied freedom of political communication (Constitutional law)
- The guarantee of acquisition on just terms (Constitutional law)
- The Commonwealth’s heads of power (Constitutional law)
- State and federal courts: Wakim and Kable (Constitutional 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. Australia is a federation: the Commonwealth, the six States and the Territories each make law, and the High Court is the final court for all of it. The common law, by contrast, is one law across the country. Each page says whether the rule is constitutional, federal or common law shared by every jurisdiction, or State-by-State legislation that varies, and flags where the States and Territories differ. Each page states the usual formulation of the rule and names landmark decisions; check the primary sources of your own jurisdiction before relying on any rule.