The media union has called Peter Dutton’s behaviour towards two ABC reporters “unnecessarily aggressive” as the public broadcaster vowed to continue to ask the opposition leader and others tough questions.

Dutton has twice clashed with ABC reporters at separate doorstops this month, and the confrontations have been amplified by Sky News which has run the press conferences in full and described the incidents as a “brutal attack” and “torching” by Dutton.

In Western Australia on Friday, Dutton accused Bunbury-based ABC reporter Bridget McArthur of being an ideological advocate and “playing games” after she asked him whether the locals in Collie supported his nuclear power plants proposal.

“I’m not interested in the politics at the ABC,” Dutton replied. “You can all be advocates and play your games.”

She had asked him: “How do you know the vast majority of the public in Collie support the plan?”

Dutton: “Well, how do you know that they don’t?”

McArthur: “Well, I have spoken to a number of them. I haven’t seen you speak to a single member of the public.”

Dutton: “I understand the position of the ABC. The ABC has an ideological position against that. That’s an issue for you. I don’t really care.”

The federal media section president of the Media, Entertainment and Arts Alliance, Karen Percy, said confrontations with ABC reporters in the lead-up to the federal election by the opposition leader were troubling.

“Journalists attend media conferences to get answers to questions on issues affecting their communities,” Percy told Guardian Australia.

Earlier this month ABC reporter Anushri Sood asked Dutton about comments he made regarding the ban on Hezbollah’s flag, with the reporter questioning why there are “no bans currently on Israeli flags being raised” at rallies “despite 45,000 people dying at the hands of the Israeli government”.

Dutton responded by demanding to know where the reporter was from and to repeat the question.

“They organise terrorist attacks and if that is not clear to the ABC, then I think the ABC is in greater trouble than even I first imagined,” Dutton said.

Percy said the opposition leader showed himself to be thin-skinned and “unnecessarily aggressive in his responses”.

“As we head towards what will be a keenly contested election we expect journalists to be respected for the job they are doing which is to hold the powerful to account and act in the public interest.”

ABC News said in a statement it stood by its reporters. “ABC journalists ask questions every day on behalf of the public,” a spokesperson said. “It’s their job to do that and they will never shy away from that.”

In relation to the Hezbollah question, the ABC said: “Hezbollah is listed as a terrorist organisation by the Australian Government and the ABC recognises that in its coverage.”

Friday’s clash with Dutton saw the ABC reporter stand her ground. “You always make it about the ABC,” McArthur said. “I don’t have a bias, you might have a bias against the ABC.

“You can ask [climate change and energy minister] Chris Bowen the kind of questions I ask him and I promise you I don’t,” she continued.

Dutton responded that she had the choice between being an “advocate or a journalist” and added that the ABC was “using” taxpayer money.

He continued: “When you’ve been employed by the ABC, I just think your job is to be impartial, and that’s not what you’re doing.”

Sources say the ABC is prepared for an election campaign marked by a tendency for politicians to act in a hostile manner towards the press or sections of the press.

The Guardian has sought comment from Dutton.