Treasurer Jim Chalmers has blasted Opposition Leader Peter Dutton as the “chief propagandist” of misinformation peddled by the anti-Voice campaign in another heated Question Time.

“The Leader of the Opposition has taken the weirdest whispers from the furthest fringes of social media and legitimised them and amplified them here in the people’s House of Parliament,” Chalmers said.

“He has seen this from the very beginning, not as a chance for unity but as an excuse to practise the usual nasty and negative, angry and dishonest and divisive politics.”

Chalmers also accused Dutton of “trying to verbal” Indigenous Australians Minister Linda Burney in a tense confrontation in the House on Tuesday.

His comments drew anger from the opposition and a warning from Speaker Milton Dick, who told Chalmers to “temper his language”.

Wednesday’s exchange came amid another heated debate on the looming referendum after Indigenous leader Marcia Langton blasted “misreporting and lies” about her Voice campaigning, amid a storm over a speech in Western Australia.

Langton said it was “deeply disappointing” to see her comments misinterpreted as labelling those who are against the Voice as racist or stupid.

It followed a story in The Australian on Tuesday that was based on a talk Langton gave in WA last Sunday. The speech was reported by the Bunbury Herald, which Langton said misrepresented her comments.

“Every time the No cases raise their arguments, if you start pulling it apart, you get down to base racism – I’m sorry to say that’s where it lands – or sheer stupidity,” she told the gathering.

“If you look at any reputable fact-checker, every one of them says the No case is substantially false, they are lying to you.”

The comments were reported by The Australian on Wednesday in a story headlined “No voters branded racist, stupid”. Dutton used an image of the story in an Instagram post that remained live on Wednesday afternoon.

Marcia Langton says she is consulting lawyers of this post on Peter Dutton’s Instagram.

The Coalition has seized on the comments, with Deputy Opposition Leader Sussan Ley repeating a call for Burney to remove Langton from the government’s referendum working group for “denigrating” the no campaign.

“We need a respectful debate,” she said.

The opposition doubled down on its pursuit of Langton on Wednesday, with Nationals MP Mark Coulton asking:

“It has been reported that a video has emerged of a member of the minister’s referendum working group, Professor Marcia Langton, stating that social workers are ‘by and large white and racist’ and ‘police are racist and get brownie points for running people up’. Does [Burney] believe Professor Langton’s comments accord with her request to act respectfully?”

Sky News Australia reports that the quotes came from a speech by Langton at the University of Queensland in July.

Earlier on Wednesday, Langton said headlines about racism did not reflect what she said at the WA forum. She said The Australian had changed it “three times I believe” and the article had been rewritten “three times”.

“Today, I will have to go to a lawyer and ask a lawyer to write to Peter Dutton, requesting that he remove this post from his Instagram because it is absolutely not true,” Langton told Radio National on Wednesday.

“I deny it absolutely. And as you say, there is a recording of what I said at the Bunbury meeting. And what I said is very clear.

“I was explaining how the No campaign is using fears and lies to to frighten No voters into voting No, that the No campaign is claiming that our proposition in the referendum will create apartheid, and so it’s very important to answer people’s questions and explain exactly how this kind of [campaign] works.”

Langton repeatedly stressed her view during her Radio National interview that most Australians are not racist.

“It is my greatest hope that the majority of Australians are not racist. And in fact, you know, having spoken to thousands of people I am absolutely convinced that most Australians are not racist,” she said.

The latest storm follows reports in the Nine newspapers that No campaign organisers are directing volunteers to use fear to dissuade voters from supporting the Voice. It sparked heated debate in Parliament, amid allegations the campaign is peddling lies to sink next month’s referendum.

Prime Minister Anthony Albanese also turned the focus on Dutton on Wednesday.

“The Leader of the Opposition has a record of deception as long as your arm. He speaks about our energy policy; this is a guy who said that business leaders were complaining to him about our safeguard mechanism when, in fact, the business community including the [Business Council of Australia] said their members supported it,” he said in Question Time.

“He told his own party room the official position [on the referendum] would be a legislated national Voice and then blindsided them by going to a press conference and getting rid of any concept of a national Voice.

“He solemnly stood up at this dispatch box and said it was a good thing that we were attending the G20 and ASEAN and participating in an international forum and said ‘when the Prime Minister leaves Australia to represent our nation we are bipartisan. We want the world to know that’.

“Then the next day he mocked it. The next day he opposed it.

“He accused the AEC of rigging the referendum.”