A plebiscite is rare in Australian history

THE QUESTION OF SAME-SEX MARRIAGE MAY BECOME THE FOURTH PLEBISCITE TO BE HELD IN AUSTRALIA. SO WHAT IS A PLEBISCITE?

* In Australia, a plebiscite (also known as an advisory referendum) is used to decide a national question that does not affect the constitution.

* It can be used to test whether the government has sufficient support from the people to go ahead with a proposed action.

* Unlike a referendum, the decision reached in a plebiscite does not have any legal force.

* Australia has held three national plebiscites: in 1916 and 1917 for the introduction of conscription during World War I. Both were defeated. The third was in 1977 to decide a national song. Advance Australia Fair was the most popular choice winning 43.29 per cent of the vote.

* No specific rules exist about the running of a plebiscite.

* It's unlike a referendum, which to be successful requires a majority of voters across the nation and a majority of voters in a majority of states - known as a double majority.

* In the event that another plebiscite was conducted, it may be that the parliament will decide on the rules of operation.

(Source: Parliamentary Education Office).