Government Statistics
Type: Democratic, federal-state system recognizing British monarch as sovereign.
Constitution: July 9, 1900.
Independence (federation): January 1, 1901.
Branches: Head of state is the governor general, who is appointed by the Queen of Australia (the British Monarch). Legislative--bicameral Parliament (76-member Senate, 150-member House of Representatives). The House of Representatives selects as head of government the Prime Minister, who then appoints his cabinet. Judicial--independent judiciary. Administrative subdivisions: Six states and two territories.
Political parties: Liberal, Nationals, Australian Labor, Australian Democrats, Australian Greens. The Liberal Party and the Nationals form the governing coalition.
Suffrage: Universal and compulsory over 18.
Central government budget: FY 2002-03--$112 billion; FY 2003-04--$118 billion.
Defense: 1.9% of GDP.
Flag: On a blue field, U.K. Union Jack in the top left corner, a large white star directly beneath symbolizing federation, and five smaller white stars on the right half representing the Southern Cross constellation.

GOVERNMENT:
The Commonwealth government was created with a Constitution patterned partly on the U.S. Constitution. The powers of the Commonwealth are specifically defined in the Constitution, and the residual powers remain with the states.

Australia is an independent nation within the Commonwealth. Queen Elizabeth II is the sovereign and since 1973 has been officially styled "Queen of Australia." The Queen is represented throughout Australia by a governor general and in each state by a governor.

The federal Parliament is bicameral, consisting of a 76-member Senate and a 150-member House of Representatives. Twelve senators from each state are elected for 6-year terms, with half elected every 3 years. Each territory has two senators who are elected for 3-year terms. The members of the House of Representatives are allocated among the states and territories roughly in proportion to population. In ordinary legislation, the two chambers have coordinate powers, but all proposals for appropriating revenue or imposing taxes must be introduced in the House of Representatives. Under the prevailing Westminster parliamentary system, the leader of the political party or coalition of parties that wins a majority of the seats in the House of Representatives is named prime minister. The prime minister and the cabinet wield actual power and are responsible to the Parliament, of which they must be elected members. General elections are held at least once every 3 years; the last general election was in November 2001.

Each state is headed by a premier, who is the leader of the party with a majority or a working minority in the lower house of the state legislature. Australia also has two self-governing territories, the Australian Capital Territory (where Canberra is located) and the Northern Territory, with political systems similar to those of the states.

At the apex of the court system is the High Court of Australia. It has general appellate jurisdiction over all other federal and state courts and possesses the power of constitutional review.
source: http://www.state.gov