Politics

The Commonwealth of Australia is a constitutional democracy based on a federal division of powers. The form of government used in Australia is a constitutional monarchy with a parliamentary system of government. Queen Elizabeth II is the Queen of Australia, a role that is distinct from her position as monarch of the other Commonwealth realms. The Queen is represented by the Governor-General at federal level and by the Governors at state level. Although the Constitution gives extensive executive powers to the Governor-General, these are normally exercised only on the advice of the Prime Minister. The most notable exercise of the Governor-General's reserve powers outside the Prime Minister's direction was the dismissal of the Whitlam Government in the constitutional crisis of 1975.
There are three branches of government:
The legislature: the Commonwealth Parliament, comprising the Queen, the Senate, and the House of Representatives; the Queen is represented by the Governor-General, who by convention acts on the advice of his Ministers.
The executive: the Federal Executive Council (the Governor-General as advised by the Executive Councillors); in practice, the councillors are the Prime Minister and Ministers of State.
The judiciary: the High Court of Australia and other federal courts. Appeals from Australian courts to the Judicial Committee of the Privy Council in the United Kingdom ceased when the Australia Act was passed in 1986.
The bicameral Commonwealth Parliament consists of the Queen, the Senate (the upper house) of 76 senators, and a House of Representatives (the lower house) of 150 members. Members of the lower house are elected from single-member constituencies, commonly known as "electorates" or "seats". Seats in the House of Representatives are allocated to states on the basis of population, with each original state guaranteed a minimum of five seats. In the Senate, each state is represented by 12 senators, and each of the territories (the ACT and the NT) by two. Elections for both chambers are held every three years; senators have overlapping six-year terms, and only half of the seats are put to each election unless the cycle is interrupted by a double dissolution. The party with majority support in the House of Representatives forms government, and its leader becomes Prime Minister.
There are two major political groups that form government: the Australian Labor Party, and the Coalition which is a grouping of two parties: the Liberal Party, and its minor partner, the National Party. Independent members and several minor parties—including the Greens and the Australian Democrats—have achieved representation in Australian parliaments, mostly in upper houses. Since 3 December 2007, shortly after the 2007 election, the Labor Party led by the Prime Minister Kevin Rudd has been in power in Canberra, and the party is now in power in every parliament in the country. In the 2004 election, the previous governing Coalition led by John Howard won control of the Senate—the first time in more than 20 years that a party (or a coalition) has done so while in government. Voting is compulsory for all enrolled citizens 18 years and over, in each state and territory and at the federal level. Enrolment to vote is compulsory in all jurisdictions except South Australia.