What is preferential voting in Australia?
Preferential voting is the system used for the House of Representatives and most state lower houses, where voters rank candidates in order of preference. If no candidate wins more than half of first preferences, preferences are distributed until one does.
Voters write the number 1 next to their first choice, 2 next to their second choice and so on. In federal lower house elections, voters must number every box for the vote to count.
If no candidate has more than 50 percent of first preference votes, the candidate with the fewest votes is eliminated. Their votes are then given to the next preferred candidate on each ballot.
Winning on preferences
This process continues until one candidate has more than half of the votes. It means a candidate who did not come first on first preferences can still win if they receive enough preferences.
The system is also called instant-runoff voting in other countries. Australia has used it for federal lower house elections since 1918.
Parties hand out how-to-vote cards suggesting how supporters might number their preferences, but voters can number the boxes however they wish. The Senate uses a different system, called proportional representation, to elect multiple members from each state.