The Australian Constitution can only be amended with the approval of Australian voters. Therefore, any proposed alteration must be put to the vote at a referendum.
Section 128 of the Constitution provides that any proposed amendment to the Constitution must be passed by an absolute majority in both Houses of the Commonwealth Parliament.
In certain circumstances, a proposed amendment can be submitted to a referendum if it is passed on two separate occasions by only one House of the Parliament.
At the referendum the proposed alteration must be approved by a ‘double majority’. That is:
- a national majority of voters in the states and territories
- a majority of voters in a majority of the states (i.e. at least four out of six states).
Since Federation, only eight out of 44 proposals to amend the Constitution have been approved (see Referendum dates and results).
Voting in referendums is compulsory for enrolled voters. In referendums, voters are required to write either ‘yes’ or ‘no’ on the ballot paper in response to each question listed.
Rules governing referendums are included in the Referendum (Machinery Provisions) Act 1984.
An issue put to the vote which does not affect the Constitution is called a plebiscite. A plebiscite is not defined in the Australian Constitution, the Electoral Act or the Referendum Act. A plebiscite can also be referred to as a simple national vote.
Governments can hold plebiscites to test whether people either support or oppose a proposed action on an issue. The government is not bound by the ‘result’ of a plebiscite as it is by the result of a Constitutional referendum. Federal, state and territory governments have held plebiscites on various issues.
Under s. 7A of the Electoral Act, the AEC can conduct a plebiscite as a fee-for-service election, with the AEC entering into ‘an agreement, on behalf of the Commonwealth, for the supply of goods or services to a person or body’. The rules for a plebiscite or fee-for-service election are normally contained in the terms of the agreement between the AEC and the person funding the election.
Military service plebiscites were held in 1916 and 1917 but, as they were not proposals to amend the Constitution, the provisions of section 128 of the Constitution did not apply. Voters in all federal territories were permitted to vote. Both the military service plebiscites sought a mandate for conscription and were defeated.