Optional preferential voting

Optional preferential voting in electorates each choosing one representative provides a middle path between first past the post and preferential voting. It has been used in New South Wales since the 1981 state election and was used in Queensland from 1992 to 2015. In both cases, Labor governments introduced optional preferential voting.

Optional preferential voting requires only that voters register a first preference on their ballot papers for their votes to be counted. Voters who wish to register one or more additional preferences among the remaining candidates are able to do so in the normal way, using consecutive numbers. Unlike full preferential voting, these voters do not have to indicate preferences among all the candidates. They can, for example, just indicate their first preference with a ‘1’ and leave the rest of the ballot blank.

Counting the votes

If no candidate gains more than 50 per cent of the first preference votes, then the least popular candidate is eliminated, as in full preferential vote counting. Any second preferences of voters who voted for that candidate are then distributed among the remaining candidates.

The ballot papers of voters who have indicated only a first preference for the least popular candidate are set aside as ‘exhausted’. These exhausted ballots no longer count as part of the total number of votes among which a winning candidate has to gain a majority. The process is repeated until one candidate gets more than 50 per cent of the remaining votes.

The following example, taken from the electorate of Kogarah at the 2011 New South Wales state election, shows how an optional preferential vote count works.

Electorate of Kogarah, 2011 NSW state election
CandidateVotes after first countVotes after second countVotes after third count
Joseph Abdel (Christian Democrats)2,507 Eliminated
Miray Hindi (Liberal)18,36019,15519,665
Cherie Burton (Labor)19,66819,92221,207 Elected
Simone Francis (Greens)3,9524,062 Eliminated
Total votes in count44,48743,13940,872
Total exhausted votes1,3483,615

Labor candidate Cherie Burton won the seat of Kogarah after the distribution of preferences from Christian Democrat and Greens voters. Over half of the Christian Demcorat and Greens voters (3,615) did not express a preference for Burton or Hindi. While Burton won 51.9 percent of the 40,872 votes that remained in the count after the distribution of preferences, she was elected with a little under 48 percent of the 44,487 valid votes cast in the Kogarah electorate.

As this example illustrates, optional preferential voting always produces a winning candidate with a majority among voters who have expressed a preference between the winner and his or her main rival. It does not, however, always produce a winning candidate supported by a majority of all voters who have cast a valid vote.