What are referendums and plebiscites?

Updated: 9 September 2015

Constitutional referendums

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.

How a Constitutional referendum works

A referendum must be held no sooner than two and no later than six months after the proposal is passed by Parliament. The main stages are:

  1. A Bill is passed by Parliament
    A Bill setting out the proposed alteration to the Constitution is passed by both Houses of Parliament. If the Bill is passed by one House but rejected, or altered, in the other (and the alterations are unacceptable to the first House) and this is repeated in the next session of the Parliament, the Governor-General may put the proposal to voters as last proposed by the first House with or without any amendments agreed by both Houses.
  2. Case committees are formed
    A majority of the Members of the House of Representatives and Senators who voted for the proposal and a majority of those who voted against it are divided into the 'Yes committee' and the 'No committee' for the referendum. These committees are responsible for a range of activities supporting a vote for or against the proposed alteration to the Constitution. When a proposal is passed unanimously by Parliament, a 'No' committee is not formed.
  3. A Writ is issued
    The Governor-General issues the Writ for the referendum. The date set for the close of rolls is seven days after the issue of the writ; and polling day, which must be on a Saturday, is not less than 33 days or more than 58 days after the issue of the writ.
  4. Information is provided to voters
    In the four weeks after the passage of the Bill, the committees are required to prepare a 'case' for voting 'Yes' and a 'case' for voting 'No'. These cases are lodged with the Electoral Commissioner, and are printed together with a statement showing the proposed alterations. This must be posted to every voter on the electoral roll, as nearly as practicable no later than 14 days before polling day.
  5. Australians vote
    Voting in a referendum is similar to casting a vote in the federal election. Polling places are established in all federal divisions, and polling day is always a Saturday. The key difference is what voters are required to write on their referendum ballot paper. In a referendum, voters are required to write either 'Yes' or 'No' in the box opposite each question on the ballot paper. If the referendum is carried, the proposed law is given Royal Assent by the Governor-General.


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.

Dates and results of the two Military Service plebiscites
Name Issue of writ Polling day Result
Military Service 18 September 1916 28 October 1916 Not Carried
Military Service 10 November 1917 20 December 1917 Not Carried

Other plebiscites which the AEC has conducted include: