"Given the majority of parliamentarians and Australians now support marriage equality, is a $160 million plebiscite necessary, and what impact do you think the debate will have on the emotional wellbeing of gays and lesbians like me?" Alastair McKenzie asked the panel via a video question.

Bridget McKenzie, who opposes marriage equality, said the Australian people could choose to have a non-damaging debate.

"I think it will only be damaging if all of us as Australians choose to actually not respect each other's views in this particular debate," she said.

The senator said the government had taken the plebiscite to the people at the election.

"I believe it is a conscience issue, and that the definition of marriage is between a man and a woman. Polls would suggest I'm in the minority."