Labor, One Nation to face off in high-stakes state by-election in WA’s Secret Harbour on Saturday

West Australians in the southern outskirts of Perth will head to the ballot box on Saturday to cast their votes in the Secret Harbour state by-election, in a test of Labor’s ability to hold its ground against One Nation.

The seat was left vacant by long-serving Labor MP and Navy veteran Paul Papalia after he quit politics in July because a member of his immediate family was “diagnosed with a serious illness”.

Mr Papalia, who spent much of his 19-year political career as a minister, said at the time: “I can’t continue to give this role everything it demands while also giving my family what they need from me.”

While electoral boundaries and names have shifted over the past 40 years, the area has been Labor safe seat.

But a late surge in One Nation’s support could change that, and everyone in Canberra will be watching.

A One Nation win in Secret Harbour would mark the first loss of a Labor stronghold to the populist minor party and set the tone for federal contests in 2028.

One Nation has vowed to run in every seat at the next federal election and is gunning for Labor’s territory in Western Australia firmly.

The populist party has already had some big wins this year, snatching former Liberal leader Sussan Ley’s seat of Farrer and picking up a number of seats at the South Australian state election.

It is also looking to unseat Liberal frontbencher Andrew Hastie, whose electorate of Canning overlaps with Secret Harbour, at the next federal poll.

Mr Hastie, a fierce critic of Senator Hanson and her party, said this week it was “really important” his state colleagues fought hard.

“We had swings towards us in the state election last year, and I had double-digit swings in the federal election,” the special forces veteran told ABC’s 7.30.

“I even flipped Labor booths – longstanding historical Labor booths – last year.

“So I think there is a strong story for the Liberal Party, but we’ve just got to fight.

One Nation has targeted Mr Hastie with “relentless personal attacks”, with the Department of Home Affairs bolstering security at his home and electorate office.