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Electing members of parliament

Representative democracy

Australia is a representative democracy which means that Australians elect members of parliament to make laws and decisions on their behalf. At a federal election, Australians elect members of parliament to represent them in federal Parliament. All Australians aged 18 years and over must enrol to vote.

The federal Parliament is bicameral which means that it consists of two houses—the Senate and the House of Representatives. There are 151 members in the House of Representatives. Each member represents an electorate in Australia. Electorates are based on population—on average, 100 000 voters live in each electorate. This means that states with larger populations have more electorates and therefore more members in the House.

The Senate has 76 senators. Each Australian state is represented by 12 senators. The states were given equal representation in the Senate so that states with larger populations did not dominate the Parliament. Since 1975, the Australian Capital Territory and the Northern Territory have each been represented by two senators.


House of Representatives

Elections for the House of Representatives use a preferential voting system to elect one member for each electorate. A candidate must get an absolute majority (more than 50% of the votes) to be elected.

Voters write a number beside the name of every candidate on the ballot paper: '1' for their first preference (or choice), '2' for their second preference and so on.

If a candidate gets an absolute majority of first preference votes, that candidate wins. If no candidate has enough first preference votes for an absolute majority, then the candidate with the fewest votes is excluded and their votes are transferred to the remaining candidates, according to voters' second preferences. This process of excluding candidates and redistributing votes continues until one candidate achieves an absolute majority.

Preferential voting in the House of Representatives

To be elected, a candidate must have an absolute majority of votes (more than 50% of the total votes). In the example below using 100 votes, the absolute majority is 51 or more.

1st count 39 35 20 6

No one has 51 or more votes, so Lauren's votes are transferred (distributed) according to second preferences.

  39 35 20 6
  1 4 1  
2nd count 40 39 21  

No one has 51 or more votes, so Joe's votes are transferred (distributed) according to the next preferences.

  40 39 21  
  6 15    
3rd count 46 54    

Ari is elected with 54 votes.


In Senate elections, Australians are voting to fill more than one vacancy. Elections for the Senate use a preferential voting system known as proportional representation. This means senators must get a ‘quota' (set number) of votes.

The number of votes required is obtained by dividing the total number of votes (in each state or territory) by one more than the number of candidates and then adding one to the result. A wider range of Independents and smaller parties are often elected to the Senate.

Calculating the quota

For electing six state senators

Senators required: 6

Total votes: 700 000 (for simplicity)

\(700\ 000 \over 6 + 1 \) + 1 = quota

700 000 ÷ 7 = 100 000

100 000 + 1 = 100 001

Quota = 100 001

Senate ballot papers list all the names of the candidates and the political parties to which they belong, followed by ungrouped or individual candidates. Senate ballot papers are divided into two sections to give people a choice of voting 'above-the-line' or 'below-the-line'.

  • Above-the-line voting means that voters have to number at least six boxes from 1 to 6 for their chosen parties or groups. Voters' preferences will be distributed in the order that the candidates in the chosen parties or groups are listed below the line. Preferences will be distributed to the party or group of first choice, then second choice and so on, until all preferences are distributed.
  • Below-the-line voting requires voters to number at least 12 boxes from 1 to 12 for their chosen individual candidates. Voters' preferences will be distributed to the candidates in the order of choice, as numbered on the ballot paper.

When are federal elections held?

Under section 28 of the Constitution, members of the House of Representatives are elected for a maximum term of 3 years, although elections may be called earlier.

State senators are elected for a period of 6 years. The Senate is elected on a rotating basis, with half the state senators elected every 3 years. The terms of territory senators are the same as the members of the House of Representatives.

When an election for the House of Representatives is called, a half-senate election is usually held at the same time. Newly-elected state senators begin their term of office on 1 July following such an election.

However, in a double dissolution election, both the Senate and the House of Representatives are dismissed (dissolved), meaning every seat in both chambers is contested. This type of election is held to resolve disagreements between the House and Senate. Newly-elected senators in a double dissolution election have their term of office backdated to 1 July prior to the election.