How Australia is governed

Section 51 of the Constitution lists the subjects on which the Commonwealth may legislate. Anything not listed stays with the states. That single design decision produces most of the everyday complexity of Australian life.

The Commonwealth runs taxation, customs, currency, defence, foreign affairs, immigration and citizenship, social security, Medicare and the Pharmaceutical Benefits Scheme, superannuation, telecommunications, corporations law and the Australian Consumer Law. It also has enormous informal power through money: it collects most of the tax revenue and then grants it to the states with conditions attached, which lets it shape policy in areas it cannot legislate on directly.

The states and territories run public hospitals and ambulance services, schools, police, prisons, courts for most criminal matters, roads, public transport, residential tenancy law, driver licensing and vehicle registration, land titles, stamp duty and land tax, workers' compensation, and the fair-trading agencies that enforce consumer law on the ground.

Local government — about 537 councils — is created by state legislation and can in principle be abolished by it. Councils handle rates, waste, local roads and footpaths, development approvals, libraries, parks and pools.

The federal Parliament has two chambers plus the monarch, represented by the Governor-General. The House of Representatives has 150 members elected from single-member divisions of roughly equal population, for terms of up to three years. Government is formed by whoever can command a majority there.

The Senate has 76 senators — twelve from each state regardless of population, and two from each of the ACT and the Northern Territory. State senators serve six-year terms with half the Senate facing election every three years; territory senators serve terms tied to the House.

What makes the Australian Senate unusual is that it is both proportionally elected and almost co-equal in power. It cannot originate or amend money bills, but it can reject them. Because the single transferable vote system reliably delivers seats to minor parties and independents, governments rarely control the Senate and must negotiate to pass legislation. This is a feature, not a malfunction: it was the price the smaller colonies extracted for joining the federation.

The 1975 constitutional crisis, in which the Senate deferred supply and the Governor-General dismissed the Prime Minister, remains the sharpest illustration of what those powers can do.

A bill is introduced, usually in the House by a minister, and read a first time. The second-reading debate covers the principle of the bill; the consideration in detail or committee stage covers the clauses; the third reading passes it. It then goes to the Senate and repeats the process, where it may be amended, referred to a committee for inquiry, or rejected.

If both houses agree on identical text, the bill goes to the Governor-General for royal assent and becomes an Act. If the Senate twice rejects a bill in specified circumstances, the Constitution provides for a double dissolution — dissolving both houses entirely — and, if the deadlock persists after the election, a joint sitting. This has happened seven times; the joint sitting only once, in 1974.

State parliaments work the same way, except that Queensland abolished its upper house in 1922 and the ACT and Northern Territory have single chambers.

Voting has been compulsory at federal elections since 1924. Enrolment is compulsory too, and the Australian Electoral Commission actively enrols people it can identify from other government data. Failing to vote attracts a modest fine unless you have a valid reason. Turnout sits above 90 per cent of enrolled voters — dramatically higher than in comparable democracies with voluntary voting.

The House uses full preferential voting: you number every candidate in order of preference, and if nobody has a majority, the lowest candidate is eliminated and their votes redistributed until someone passes 50 per cent. This means a vote for a minor party is never 'wasted' — it flows on. It also means the two-party-preferred result, not the primary vote, decides seats.

The Senate uses a single transferable vote across the whole state as one electorate, with above-the-line and below-the-line options. Because a quota is roughly 14.3 per cent of the vote in a normal half-Senate election, minor parties and independents win seats regularly.

Section 128 sets an unusually high bar. A proposed alteration must pass both houses of Parliament (or one house twice), then be put to a referendum where it must win a national majority of voters and a majority in a majority of states — at least four of the six. Territory votes count towards the national total but not towards the state count.

Of 45 proposals put since 1901, only eight have succeeded. The most emphatic was the 1967 referendum on Aboriginal Australians, carried with 90.77 per cent support. The most recent, the 2023 proposal for an Aboriginal and Torres Strait Islander Voice, was defeated with about 60 per cent voting no and no state in favour.

The practical effect is that Australia's constitutional text has changed very little, and the High Court's interpretation of it has done most of the work of adapting the document to a country the 1890s framers would not recognise.

King Charles III is King of Australia in a legal capacity entirely separate from being King of the United Kingdom. The Australia Acts of 1986 severed the last legislative and appellate links to Britain, so no UK institution has any role in Australian government.

The Governor-General exercises the Crown's powers domestically — giving assent to legislation, appointing ministers, and acting as commander-in-chief in a formal sense — almost always on the advice of the Prime Minister. A small set of 'reserve powers' can, in contested circumstances, be exercised without advice. Their existence and limits are not written down, which is precisely what made 1975 so contentious.

A 1999 referendum on becoming a republic was defeated, with 45.13 per cent in favour. The result is generally read less as settled support for the monarchy than as disagreement about the specific model on offer, in which the President would have been appointed by a two-thirds majority of Parliament rather than directly elected.