Hughes MP Craig Kelly and Labor frontbencher Tanya Plibersek have gone toe to toe in front of the TV cameras after she told him his "crazy" views could stop people getting a COVID-19 jab.
For several minutes, the two MPs argued the point after Ms Plibersek stopped Mr Kelly in the corridor of the Press Gallery in Parliament House, where both were doing media interviews.
Ms Plibersek, who was the Health Minister in the last Labor government, told Mr Kelly she wanted him to stop "spreading these crazy conspiracy theories" as they could cause doubt about COVID-19 vaccines.
"My mum lives in your electorate and I don't want her exposed to people who are not going to be vaccinated because of these crazy conspiracy theories that you're spreading," she said.
Ms Plibersek threw her head in her hands as Mr Kelly asked her to listen to "our most senior immunologist", Professor Robert Clancy.
"Listen to him, go and get his stuff, read what he is saying and then you can come and apologise to us," he said.
Emeritus Professor Robert Clancy, of the University of Newcastle, told The Sydney Morning Herald this week he did not agree with everything Mr Kelly said but thought he was "absolutely right" in advocating the drugs hydroxychloroquine and Ivermectin as COVID-19 treatments.
"Early treatment is highly effective," Professor Clancy said. "Vaccines are critically important. They should not be seen as mutually exclusive. You need them both."
Last month, Commonwealth Chief Medical Officer Paul Kelly said there was not enough evidence to show the two drugs should be used.
Ms Plibersek asked Mr Kelly whether Prime Minister Scott Morrison agreed with his views.
"I don't know, you will have to ask him," Mr Kelly replied.
Ms Plibersek said, "I agree with your Prime Minister and your Health Minister."
Speaking at the National Press Club on Monday, Mr Morrison faced a question about government MPs who were "spreading disinformation" about both the virus and vaccines on social media.
Mr Morrison said people should get their information from official government sites, not Facebook.
When Mr Kelly's name was raised, Mr Morrison said, "He's not my doctor and he's not yours. But he does a great job in Hughes."
Mr Morrison reportedly spoke to Mr Kelly about his views before the first day of the new Parliamentary session on Tuesday.
The government voted down a Labor motion calling for Mr Morrison to condemn Mr Kelly for his "dangerous and irresponsible" comments, "which have the potential to undermine public confidence in the upcoming rollout".