Quick questions on The Constitution, separation of powers and division of powers: QCE Legal Studies

The Constitution of the Commonwealth of Australia is contained in s 9 of the Commonwealth of Australia Constitution Act 1900 (UK). It entered into force on 1 January 1901, federating the Australian colonies into the Commonwealth.

The Constitution distributes power between three institutions:

The Constitution divides legislative power between the Commonwealth and the states.

:::tldr The Constitution structures Australian government through the separation of powers (legislative under Chapter I, executive under Chapter II, judicial under Chapter III) and the division of powers between the Commonwealth and the states (exclusive, concurrent and residual). The Engineers Case (1920) re-set constitutional interpretation in favour of Commonwealth supremacy in concurrent areas under s 109. :::

Section 1 vests legislative power in a Federal Parliament consisting of the Queen, the Senate and the House of Representatives. Section 51 lists the heads of legislative power (40 paragraphs covering taxation, trade and commerce, corporations, defence, marriage, divorce and matrimonial causes, external affairs, etc.).

Section 61 vests executive power in the Queen, exercisable by the Governor-General. The executive includes the Prime Minister and Cabinet, the federal public service, the Australian Defence Force, and statutory authorities.

Section 71 vests the judicial power of the Commonwealth in the High Court of Australia and such other federal courts as Parliament creates. Section 75 sets out the original jurisdiction of the High Court.

Australia operates a system of responsible government: ministers must be members of Parliament. The same individuals therefore exercise both legislative and executive power. The strict separation between legislature and executive is therefore largely theoretical in Australia.

Only Chapter III courts can exercise Commonwealth judicial power. Non-judicial functions cannot be conferred on Chapter III courts. R v Kirby; Ex parte Boilermakers' Society of Australia (1956) 94 CLR 254 (the "Boilermakers' Case") set the rule.

Powers reserved for the Commonwealth alone:

Most of s 51. Both the Commonwealth and the states can legislate. Where they conflict, s 109 of the Constitution resolves in favour of the Commonwealth.

Everything not granted to the Commonwealth remains with the states. This includes criminal law (largely), education, health services, transport, environment (in part), property law and family violence law.