Peter Dutton has advised anti-voice campaigners to avoid national rallies involving a pro-Putin commentator.
The demonstrations, due to take place across the country on Saturday, are to be led by Simeon Boikov, an online commentator who posts anti-vaccine and pro-Putin content.
The official 'no' campaign has distanced itself from Mr Boikov, with the federal opposition leader urging anti-voice supporters to not attend the rallies.
"Anybody who's pro-Putin has significant issues and they should seek help for those issues," Mr Dutton said.
"I would encourage people to go to peaceful, lawful rallies, conducted by 'no' campaigners and listen to the very serious concerns and hesitations that those people have."
The pro-voice Uluru Dialogue has condemned Mr Boikov, saying his rallies demonstrate how the 'no' campaign benefits from division and disunity.
"It is not only divisive but outright dangerous for leaders of the 'no' campaign to turn a blind eye while Simeon Boikov ... exploits the voice referendum for his own gain," a statement from Pat Anderson and Megan Davis read.
"These rallies are an affront to Australian democracy."
NSW Liberal Democrat MP John Ruddick will lead one of Saturday's marches in Sydney.
The rallies come three weeks out from the referendum on an Indigenous voice to parliament.
Remote voting starts on Monday with 61 sites set up across the country, eventually covering 750 locations in the lead-up to the October 14 poll.
More than 17.67 million people have enrolled to vote in the referendum, ensuring 97.7 per cent of eligible Australians will have their say.
Australian Associated Press