The same-sex marriage debate has intensified into a row over in-vitro fertilisation and sperm donors after a ‘No’ campaigner claimed parenting was not the same as birthing children.

ABC’s Q&A program on Monday night nutted out the arguments on each side of the postal survey when an audience member asked why ‘No’ spokesperson Karina Okotel couldn’t accept his family.

“When I was younger, my mother and father separated. I live in two families. On one side of my family I have two mums, lesbian parents. On the other side I have a mother and a father, heterosexual parents,” audience member Patrick Cairnduff said.

“I’ve experienced both same-sex and opposite sex families. Both my families are loving ones. From my position, experiencing both types of families, I can see that what matters is the love and support I receive from both of them, not the form that comes in. Why can’t you accept that?”

Ms Okotel said her position had been misunderstood, as she did “accept” and “applaud” both of the loving families.

Actor and comedian Magda Szubanski – the sole LGBTI panellist – then pressed Ms Okotel on her views on same-sex families.

“You say the problem with marriage is it will lead to problems with children. That vulnerable children are threatened, I’ve read you saying this over and over that one of the consequences you have spoken about is if we pass through marriage then same-sex people will have children. That’s what you’ve said,” Ms Szubanski pressed.

“That’s very different to parenting and being raised by same-sex parents. Absolutely,” Ms Okotel responded, to groans from the audience.

She continued: “There are good parents who are heterosexual and there are good parents who are same-sex attracted. There are bad parents who are heterosexual and bad parents who are same-sex attracted.

“But if we are introducing a new institution where same-sex people can get married, marriage is for founding a family, having a family.

“What that means is therefore there would be rights for same-sex people to have children and the only way to do that is through the use of assisted reproductive technology. That raises issues in terms of not knowing your biological parent.”

Same-sex couples in Australia already use assisted reproductive technologies to have children.

Ms Szubanski took Ms Okotel to task over the claims.

“Do you have the same issue with straight people who use IVF? One in six couples have a fertility issue. Are you going to dictate who can and can’t have children, not just gays?” the actor asked.

“So if you have an issue with IVF, is it just with gay people having IVF, or straight people?”

Ms Szubanski later refuted claims from an audience member that same-sex marriage would alter society’s view of men and women, saying that gay people were a “really small percentage of the population”.

“You can’t breed us out of existence because we do originate mostly from straight people. But there does seem to be a constants number of roughly 10% of same-sex attracted people,” she said.

“It’s not like there’s an army of us who are going to take over. We just want to have the same rights and protections.”

Questioner Danielle Hewitt, a doctor training in developmental paediatrics, cited research that the structure of families and knowing biological parents did not change outcomes for children.

“What would it take for the ‘No’ campaign to stop insinuating that there is harm in other family structures and causing stigmatisation to those families?” she asked.

Panelist Glenn Davies, the Anglican Archbishop of Sydney, said the nurturing styles of mothers and fathers were complementary to one another.

Host Tony Jones then asked why this was part of a debate on same-sex marriage when it was already the case that children were raised without both their biological mother and father.

“Why is it part of a debate about same-sex marriage at all, since it’s already happening?” Mr Jones asked, to applause from the audience.