The Liberal Party’s break with its Howard-era policy of not doing preference deals with One Nation has revived interest in the right-wing minor party’s prospects at this Saturday’s election.

Even before the deal, polls were looking relatively good for One Nation at about 7 or 8% – up from 5% in 2022 and 3% in 2019. Some of that may be a result of Trumpet of Patriots not polling as well as its predecessor, the United Australia Party, did last time.

Liberal politicians have also softened their rhetoric about One Nation – with candidate Benson Saulo saying “One Nation is a centre-right party” like the Liberals. Former MP Tim Wilson, who in 2019 professed “a longstanding view that we should put One Nation and their despicable acolytes last”, has preferenced One Nation ahead of independent MP Zoe Daniel and the Greens candidate.

This realignment on the right of Australian politics could have long-term consequences for the country, regardless of the specific electoral outcomes on Saturday.

And while much commentary has focused on the House of Representatives, it is actually in the Senate (where One Nation already has two senators) where Liberal preferences could make the greatest difference one way or the other.

A weakness of the new Senate voting system is that many Australians stop preferencing after just 6 parties. That means that a share of the vote is exhausted before it decides the final senators elected in a state. Back in 2019, Richard Denniss wrote about the importance of numbering every box if you want your vote to count at full strength.

Senate

It is in the Senate where One Nation’s prospects are better, and where Liberal Party preferences could make the difference. Senator Malcolm Roberts is defending his seat in Queensland, and the party claims it could win in other states as well.

Ben Oquist (the Australia Institute’s former Executive Director) has conducted Senate analysis showing “One Nation is the story” with the party polling well enough to potentially win in NSW, WA and SA as well as Queensland – though he notes that the party often underperforms its polling.

Success in more than one state would increase One Nation’s relative numbers, and success in all four would represent a high point for One Nation in the Senate.

House of Representatives

For minor parties running in the House of Representatives, seat gains depend on how well they do in target seats, not how many votes they get nationally. Seats to look out for include Hunter and Paterson (Hunter Valley in northern NSW) and Flynn (around Gladstone in Queensland), all seats where One Nation did well in 2019.

One Nation is running the same candidate in Hunter this year as they did in 2019. At that election, One Nation won 22% of the primary vote, just behind the Nationals on 23%. Labor’s Joel Fitzgibbon won 45% of the primary vote and ended up on 53% in two-party preferred terms (after preferences are distributed).

For One Nation to be competitive for the seat this time, they would have to stay in the count longer than the Nationals candidate – and then receive most of that candidate’s preferences. That most likely would require a higher primary vote than the Coalition candidate, which they’ve so far failed to

achieve in the seat. Even then, Labor’s Dan Repacholi would have to do a fair bit worse than the party did in 2019 for the seat to fall (he won 54% of the two-party preferred in 2022).

Do Coalition voters tend to preference One Nation or Labor higher? Unfortunately, the data is patchy. The limited data we could find suggests more Coalition voters preference One Nation than Labor, but it’s not consistent between elections or seats. That’s because political parties are free to recommend preferences via how-to-vote cards, but each voter decides how they allocate their preferences.