The campaign against an Indigenous voice is facing pressure to reveal details of two volunteers sacked for expressing racist views.
Leading 'no' campaigner Warren Mundine confirmed he had "kicked people off" the campaign because of racist comments.
Mr Mundine declined to name them, but said two people had been removed from the campaign because he heard them say something racist.
"They're not prominent people, they were people who were working for us as volunteers," he told ABC Radio on Tuesday.
"I've gotten rid of them and I don't accept any racial comments from anyone in regard to these issues."
Mr Mundine said the remarks weren't about Indigenous people, but one was a "very anti-Semitic comment".
But the Liberals for Yes group said Mr Mundine had raised more questions than answers.
In a statement, the group called on the 'no' campaign to immediately release further details about the sackings.
"This referendum debate is too important, and the eradication of racism too essential, for political cover-ups and secret sackings to be allowed to remain in the cover of darkness," the statement said.
Attorney-General Mark Dreyfus said there was increasing "hysterical" misinformation coming from the 'no' campaign.
He urged Opposition Leader Peter Dutton to distance himself from hateful messaging.
"The 'no' campaign wants to talk about everything but the actual proposal," he said.
"The 'yes' campaign is talking about what the proposal actually is, a simple and significant change to our constitution which is about recognition and listening."
Support for the voice is continuing to slip, as polls show a mirroring decline in voter sentiment towards the prime minister.
A Resolve Political Monitor poll conducted for the Sydney Morning Herald found support for the voice had declined from 48 to 46 per cent, on the 'yes' or 'no' question.
This means support is down from 63 per cent one year ago.
Poll results indicated the voice had majority support in Victoria and Tasmania, but not in NSW, Queensland, Western Australia or South Australia.
To succeed, the 'yes' campaign will require more than 50 per cent of the vote across the nation and in four of the six states.
But Mr Dreyfus said he wasn't concerned about what the polls showed months out from the vote.
"I have confidence that Australians will see that this will make us a better country," he said.
Mr Dutton said the prime minister was "way off the pace" in terms of the public view on the voice.
"I understand the scepticism that's out there," he told Nine's Today program.
"Everybody wants a better outcome for Indigenous Australians, but I think people are really worried about a new layer of bureaucracy and whether it would give the practical outcomes in Indigenous communities that we all really want."
A referendum to enshrine an Indigenous voice in the constitution is expected to be held in October.
