Opposition frontbencher Andrew Hastie has called Pauline Hanson and Barnaby Joyce “lying cowards” in an escalating stoush over a One Nation video that repeatedly describes him as a “traitor”.

Mr Hastie has challenged Senator Hanson and Mr Joyce to “own” the accusation or delete the video, which took aim at his involvement in the Ben Roberts-Smith defamation case.

Mr Hastie, a former SAS officer who served in Afghanistan, was subpoenaed to give evidence in the 2022 trial and has defended doing so as consistent with the rule of law and standards expected of Australian soldiers.

In an email to supporters on Tuesday, Mr Hastie said One Nation had “picked a fight with the wrong veteran”.

In response, Senator Hanson told The Nightly she had “never called him a traitor” but would “call him a wanker”.

An older woman with short red hair and beige blazer next to middle aged man in suit smiling and walking.

One Nation’s Pauline Hanson and Barnaby Joyce both denied calling Mr Hastie a traitor. (ABC News: Callum Flinn)

Mr Joyce on Wednesday stood by this denial and suggested Mr Hastie was being “emotional” due to the electoral threat One Nation posed to his West Australian seat of Canning.

“I spoke to Pauline this morning about this, and she never called him a traitor,” Mr Joyce said.

Ms Hanson later said Mr Hastie was making a “mountain out of a molehill”.

“I’m not calling him a traitor to his country … I never said that and I have not said that. It is a satirical cartoon for Christ’s sake,” she told News24.

“I’m not going to delete the cartoon. I encourage people, if you want to go and have a look at it yourself.”

Hastie says ‘traitor’ accusation a ‘slur’ on veterans

Earlier Mr Hastie presented screenshots of the video as a “receipt” to support his claim that the two One Nation members were “lying”.

He said Ms Hanson had posted the cartoon to her X account in which he was described as a “traitor” eight times as well as a “gutless maggot”.

“I am proud of my service to this country, in uniform and in this parliament,” Mr Hastie said.

“It’s a slur on me, it’s a slur on other veterans who have given under oath evidence to the federal court.”

Mr Hastie said One Nation must either delete the video or “own” the accusation made against him.

“Your choice,” he said.

Mr Joyce responded to this challenge on Wednesday afternoon, telling the ABC he had never called Mr Hastie a traitor or “ventured anywhere close to any such statement about him”.

“Paradoxically, this morning in a press conference at Canberra I spoke in support of Mr Hastie and his family,” Mr Joyce said.

“When asked, I noted the fact that Ms Hanson stated to me she had never called Mr Hastie a traitor.

“This is now apparent as a fact; she hasn’t.”

Mr Joyce said it had since come to his attention that a “satirical cartoon” had made the claim.

“I had not seen it nor was I aware of it,” he said.

One Nation accused of politicising Ben Roberts-Smith case

Mr Hastie has been the target of One Nation criticism over his decision to testify in the defamation case brought by Mr Roberts-Smith, a former SAS soldier and Victoria Cross recipient who is now fighting war crimes charges.

Mr Roberts-Smith lost his case against the Nine papers in 2023 after the Federal Court found, on the civil standard of the balance of probabilities, that allegations he was involved in unlawful killings in Afghanistan were substantially true.

He has since been charged with five counts of the war crime of murder over the alleged killings of five Afghan men between 2009 and 2012, which he has denied.

Ben Roberts Smith in a blue suit, white shirt, outside court on a sunny day.

Former SAS corporal Ben Roberts-Smith has been charged with five counts of the war crime murder, which he denies. (AAP: Bianca De Marchi)

Senator Hanson has repeatedly vocalised her support for Mr Roberts-Smith, vowing not to “abandon” him.

Her party has also campaigned with posters declaring “One Nation stands with him”.

Mr Hastie has accused One Nation of politicising the case.

“I stand with a lot of Australians who believe in the rule of law, who believe that Australian soldiers should be held to high standards of battlefield conduct,” he said.

“Pauline Hanson and Barnaby Joyce have never, ever served a day in our uniform overseas on operations.

“They don’t get to define Anzac Day or Anzac or the values that underpin our defence force.”

One Nation ‘picked a fight with the wrong veteran’

Earlier this week, Mr Hastie vowed to make the fight for his seat a “costly exercise” in time, money and political capital for One Nation, declaring the party would at best achieve a “Pyrrhic victory”.

The shadow industry minister’s seat of Canning covers a large part of the state electorate of Secret Harbour, which One Nation won in a by-election last month.

Senator Hanson has made no secret of her desire to win Mr Hastie’s seat at the next election, prompting a WA paper to splash “I’m Canning for you next” on its front page over the weekend.

Ben Robert-Smith trial

The former girlfriend of Ben Roberts-Smith has been asked about her pregnancy and miscarriage in court, while sobbing in the witness box

Speaking on Wednesday, Mr Hastie said he was going to fight “exceptionally hard” to hold onto Canning against both One Nation and Labor at the next election in 2028.

“I’m not worried about losing my seat; I’m worried about being called a traitor after serving my country,” he said.

Mr Hastie said One Nation had “picked a fight with the wrong veteran”.

“They thought I’d just lie down and cop it; guess what, you’ve unlocked an achievement, and I’m going to fight all the way,” he said.

Amid the One Nation row, Liberal MP Garth Hamilton said he was “proud” to support his colleague Mr Hastie.

“He has a strong record of fighting against Labor which shines in contrast to One Nation’s disgraceful history of attacking conservative politicians,” he said.