For close to 30 years, Pauline Hanson’s One Nation party has been hanging over the heads of the major parties like the Sword of Damocles.

Since One Nation’s success in the Queensland state election of 1998 (when the new party won 11 seats with a primary vote of 23%), there’s been an expectation the party would be winning seats in parliaments across Australia, following a similar trajectory to populist radical right breakthroughs in other countries around the world.

Of course, circumstances have meant that One Nation’s trajectory has gone through peaks and troughs since then. Labor and the Coalition’s strategy of refusing to direct preferences to One Nation thwarted its national campaign in 1998 just as it threatened to truly take off, while One Nation’s organisational disintegration throughout the early 2000s meant it was just not a competitive force in subsequent contests.

Since Pauline Hanson’s return to federal politics in 2016 by way of winning a Queensland Senate seat, One Nation has once again been prominent the Australian political landscape.

 The party’s recent election in South Australia, gaining approximately 23% of the primary vote, and its performance in opinion polls in the past few months suggest the party – almost three decades after its establishment – now stands as the biggest threat to the established parties.

In Victoria, for example, One Nation’s primary vote is hovering at more than 20%. At the national level, One Nation’s support is closer to 25%. 

That is why the upcoming byelections in New South Wales and Victoria are critical to determining the future of One Nation in Australian politics. 

In Farrer, a dozen people have nominated, including candidates from the Liberal Party, Nationals, Greens and One Nation. The seat has been a stronghold for the Coalition and was held by former deputy prime minister Tim Fischer until 2001 when it was won by Liberal Sussan Ley.

Michelle Milthorpe, the independent who performed strongly in the 2025 general election, is expected to be competitive, even though the Liberal and National parties have promised to preference One Nation before Milthorpe. 

If One Nation was to ever win a lower house seat in the Parliament of Australia, it would have to be this particular byelection – the conditions suit them as well as they might ever suit them. The political debate plays to the party’s core focus – migration, housing affordability, national security, energy, and sovereignty have all been at the centre of national politics.

Additionally, the fact that the Labor Party is not contesting the regional electorate provides a cohort of voters who will be forced to choose a candidate they would not otherwise support. The extent to which One Nation is preferred over the Coalition will be easy to identify through the results.

Similarly, circumstances are favourable for One Nation in the electorate of Nepean in the Victorian Legislative Assembly. Like the Farrer byelection, Labor has made the tactical decision to not stand a candidate. 

Eight candidates will be running in Nepean, including the Liberal, Greens and One Nation parties. The Liberal Party has struggled to gain support in Victoria, though it did manage to win Nepean off Labor in 2022.

The byelection will test the extent to which Victorians have turned away from the Coalition, and One Nation’s popularity in opinion polls suggests this contest may be close.

Combined with this, One Nation has arguably never received as much positive coverage from the press as now. There’s a self-fulfilling cycle taking place – the more attention the party is given, the more it’s seen as a “serious” contender, which in turn garners more press attention. 

These byelections will not just be a test for the Coalition, but will be a defining moment for One Nation. If Hanson’s party was to win these two seats, it can establish a foothold for potentially sustainable parliamentary representation in the lower houses of the national and Victorian parliaments.

Failure to win, however, may stop the narrative established from the momentum of the South Australian election in its tracks.

Will we look back at these byelections as the high watermark of One Nation’s success, or as the moment the floodgates opened into lower house representation?

It’s now over to the voters in Farrer and Nepean to make, or break, One Nation.