The Parliament of Australia, also known as the Commonwealth Parliament or Federal Parliament, is the legislative branch of the government of Australia. It is bicameral, largely modelled in the Westminster tradition, but with some influences from the United States Congress. According to Section 1 of the Constitution of Australia, Parliament consists of three components: the Queen, the Senate, and the House of Representatives. The Queen is almost always represented by the Governor-General.
The lower house, the House of Representatives, currently consists of 150 members, who represent districts known as electoral divisions (commonly referred to as "electorates" or "seats"). The number of members is not fixed, but can vary with boundary changes resulting from electoral redistributions, which are required on a regular basis. The most recent overall increase in the size of the House, which came into effect at the 1984 election, increased the number of members from 125 to 148. It reduced to 147 at the 1993 election, returned to 148 at the 1996 election, and has been 150 since the 2001 election. Each division elects one member using compulsory preferential voting. The upper house, the Senate, consists of 76 members: twelve for each state, and two for each mainland territory. Senators are elected using a form of proportional voting. The two Houses meet in separate chambers of Parliament House on Capital Hill in Canberra. The present Parliament is the 43rd Federal Parliament since Federation.