Scott Morrison has suggested George Christensen go "quietly into retirement", following the Queensland MP's remarks on a far-right online show criticising Australia's COVID-19 response.
Mr Christensen, who is quitting federal politics at the next election, made an appearance on US conspiracy theorist Alex Jones' InfoWars program, where he urged for protests outside Australian embassies due to the country's pandemic restrictions.
He also laughed when comparisons were made between Australia's quarantine facilities and the Auschwitz concentration camp.
The prime minister said he strongly condemned the remarks.
"I thought those comments were appalling, and I have spoken to George directly about them," Mr Morrison told reporters in Sydney on Wednesday.
"George is not a candidate for the LNP at the next election, and I think George should quietly go into retirement."
Nationals MP have insisted Mr Christensen's comments do not represent the views of the party.
However, Victorian MP Darren Chester stopped short of calling for him to be stripped of his party membership.
"I don't want to wish ill of anyone, but I think his time in parliament has passed, and it won't be a sad day for me when he's no longer a member of parliament," he told the ABC on Wednesday."
"Each of the state jurisdictions holds their members of parliament to account, so it's up to the executive of the (Queensland) LNP to hold George to account."
Treasurer Josh Frydenberg, whose parents are Jewish immigrants, said he had spoken with Mr Christensen following his appearance on the show.
"I rang George yesterday and spoke to him and he did apologise to me, and I reminded him about the importance of our comments," he told the Seven Network on Wednesday.
"We have a collective responsibility and duty to speak out about these very false analogies."
Meanwhile, a second government MP has come under fire for appearing on another US far-right program hitting out at Australia's restrictions.
South Australian Liberal Senator Alex Antic spoke on former US president Donald Trump advisor Steve Bannon's War Room: Pandemic podcast.
On the podcast, the senator said state governments were drifting into authoritarianism and that he was being held by health authorities in a detention facility.
Senator Antic appeared on the podcast from hotel quarantine in Adelaide, where he was taken after returning from Canberra following the end of the last parliamentary sitting week.
Unvaccinated arrivals to South Australia from interstate are required to undergo 14 days of hotel quarantine.
Senator Antic has declined to reveal his vaccination status.
Australian Associated Press