'No' campaign ad doctor unrepentant as petition for de-registration taken down

An online petition calling for the deregistration of a doctor who appears in the No campaign for same sex marriage has been pulled.

In the TV campaign, Dr Pansy Lai said a Yes vote would lead to same sex lessons in schools.

"When same sex marriage passes as law overseas, these types of program become widespread and compulsory," she claims in the ad.

A Melbourne activist posted a petition online calling for Dr Lai to be deregistered, with 6000 people signing.

Social media comments turned nasty in the wake of the advertisement, with one person saying it was "overly obvious" that Dr Lai was biased against the LGBT community.

"There have been all sorts of threats levelled against anyone who sticks their head above the parapet in this debate for preserving their definition of marriage," Christian Lobby spokesperson Lyle Shelton said.

Some question whether medical professionals should publicly voice their opinions on same sex marriage.

"I've got grave concerns about any medical practitioner who has deeply conservative and sometimes offensive views towards same sex-attracted people," Greens senator Dr Richard Di Natale said.

Dr Lai is a paediatrician in Hornsby and was too busy seeing patients to speak on camera with 7 News.

She said that she would continue to campaign against same sex marriage, saying that people need to know the "consequences" of voting Yes.

• Petition calls for doctor in 'no' campaign same-sex marriage ad to be deregistered

• 'Yes' campaign responds to 'No' camp with counter-ad on same-sex marriage

• 'You can say no': First anti-gay marriage ad airs in Australia

"This is a simple question about civil marriage and whether all Australians are allowed the same right to access it," Yes campaign director Tiernan Brady said.

A High Court challenge to the postal plebiscite begins on Tuesday.