Foundations of the Australian legal system: history, sources, the Constitution, federalism, the territories and the rule of law

British settlement began in 1788. The colonies received English law as the law of settled colonies, so English statutes and common law applied so far as they were suited to local conditions. The doctrine of terra nullius, the idea that the land belonged to no one, was the legal basis for this reception, and it was rejected by the High Court in *Mabo v Queensland (No 2)* (1992), which held that the common law recognises native title (Module 4). Each colony developed its own parliament and courts during the nineteenth century, and the six colonies federated on 1 January 1901 under the Commonwealth of Australia Constitution Act 1900 (UK).

Legal independence came in stages. The Statute of Westminster 1931 (adopted by Australia in 1942) freed the Commonwealth Parliament from the constraint of British legislation. Appeals to the Privy Council from the High Court were ended in 1968 and 1975, and the Australia Acts 1986 (passed by the Commonwealth and the United Kingdom) ended the remaining British role in state law and removed appeals from state courts to the Privy Council. Since then the High Court is the final court of appeal, and the common law of Australia is its own. Australian courts still treat decisions of the courts of the United Kingdom, Canada and New Zealand as persuasive, and often follow them, but they are not bound.

The Constitution creates a federation and divides power between the Commonwealth and the states. It sets up the Parliament (Chapter I), the executive government (Chapter II), the judicature (Chapter III) and finance, trade and the states (Chapters IV and V), and contains a few express rights. It is a document of limited, enumerated powers: the Commonwealth has only the powers the Constitution gives it, and the states keep their other powers (section 107). Like any statute, it has supremacy: a Commonwealth Act that goes beyond the Constitution is invalid, and the High Court decides whether it does.

The method of interpreting Commonwealth powers changed with the *Engineers Case* (*Amalgamated Society of Engineers v Adelaide Steamship*, 1920). Before it, the Court read the powers narrowly in order to protect the states, through implied ideas such as ‘reserved state powers’ and an implied immunity of each government from the laws of the other. The Engineers Case rejected those ideas and held that the Constitution should be read according to the ordinary meaning of its words and the settled rules of interpretation, giving each power its full natural scope. The result has been a long and steady expansion of Commonwealth power, for example through the corporations power (upheld in the Work Choices case in 2006) and the external affairs power, which lets the Commonwealth implement treaties (*Commonwealth v Tasmania*, the Tasmanian Dam case, 1983).

The territories (the Northern Territory and the Australian Capital Territory, and external territories) are not states. The Commonwealth has the power to make laws for them under section 122, and has used it to create self-governing legislatures by ordinary Acts (the *Northern Territory (Self-Government) Act 1978* and the *Australian Capital Territory (Self-Government) Act 1988*). Those Acts can be amended or overridden by the Commonwealth Parliament in a way that a state’s powers cannot. Territory laws are made by the territory legislatures within the powers delegated to them, and territory courts, such as the Supreme Courts of the Northern Territory and of the ACT, apply them.

The rule of law is an assumption of the Constitution, as Dixon J said in *Australian Communist Party v Commonwealth* (1951): the Constitution is framed on the assumption of the rule of law, and the High Court enforces the limits of power in the courts. It means that government must act under authority of law, that law applies to the government as it does to citizens, and that disputes about legality are decided by independent courts. The principle of legality is a rule of statutory interpretation that protects fundamental rights and freedoms. Courts will not interpret a statute as taking away a fundamental right, freedom or immunity, or as overriding the general principles of the common law, unless Parliament has made its intention clear with unmistakable and unambiguous language (*Coco v The Queen*, 1994). It does not stop Parliament from legislating, but it forces Parliament to speak plainly when it does. It applies, for example, to rights such as access to the courts, procedural fairness, the privilege against self-incrimination and the presumption of innocence.