strategic voting

It has long been a given of Australian politics that support for the two major parties is higher in the House than the Senate.

But that rule was broken at the 2025 Federal election when Labor polled half a percent higher in the Senate, 35.11% to 34.56% in the House.

The lower rate of informal voting for Senate elections means there were an additional 380,953 formal votes in the Senate. But of those extra votes, Labor recorded more than half, polling 218,890 more Senate votes than House votes.

More telling was where Labor’s Senate vote was stronger.

Labor’s higher Senate vote is down almost entirely to the 14 divisions that finished as contests between Coalition and Independent candidates. In these seats Labor recorded just under 250,000 more Senate votes than House votes.

Compare this to the other 136 divisions where Labor recorded around 31,000 fewer votes in the Senate than the House.

In these 14 contests, Labor’s Senate vote was 2.1 times its House support, Greens support 1.8 times higher. Compare these ratios to the Coalition polling roughly the same vote at both elections in these seats.

There are only two seats in the country where Coalition supporters showed similar rates of split voting. In Independent held Fowler in western Sydney the Coalition’s Senate vote was 1.7 times its House vote. In Calwell where Labor was challenged by an Independent, the Coalition’s chamber ratio was 1.4.

The pattern of support reveals clear evidence of Labor supporters changing their House first preference vote to engage in strategic voting. Labor voters backed Labor in the Senate, but in the House voted for Independents with a better chance of defeating the Coalition.

Strategic voting has long been a feature of simple majority voting elections in countries such as the United Kingdom. At UK elections, in seats where a voter’s preferred party can’t win, voters have learnt to vote strategically. They cast a vote for the candidate most likely to defeat their least preferred candidate rather than vote for their preferred party’s candidate who can’t win.

The UK Conservative Party has at times suffered from UK Labour and Liberal Democrat supporters switching party with the intent of defeating the Conservative candidate.

In Australia, preferential voting has allowed parties to compete against each other without splitting the vote. Liberal and National candidates, and Labor and Greens candidates, can compete for votes with preferences then reducing the contest to a left versus right contest.

But the emergence of Independent candidates, especially so-called ‘Teal’ candidates, has created a different dynamic. Independents have shown an ability to poll well and defeat Coalition candidates on strong flows of Labor and Green preferences.

But to do so, Independents must first outpoll the Labor candidate on primary votes. Which is where strategic House voting by Labor and Greens supporters in voting Independent is flipping contests against the Coalition.

The seat-by-seat difference in Labor and Green support in the two house is clear evidence that strategic voting exists in Australia, and it is becoming a major problem for the Coalition, in particular the Liberal Party.Read More »FED2025 – Evidence on Labor Supporters Voting Strategically for Independents