By Amy Remeikis
The "yes" campaign has dedicated its first salvo in the same-sex marriage debate, arguing the only people who will be affected by changing the Marriage Act, are those who are gay.
But conservative senator Matt Canavan said he remains concerned same-sex marriage was only the "first step" in a wider change of society's values, and argued relationships between males and females deserved "a special word and a special institution" for their ability to produce children.
The Coalition for Marriage released its first television advertisement on Tuesday opposing any change to the definition of marriage, by claiming a "yes" vote would lead to children being forced to learn radical gender and sex theories.
In its first advertisement, released on Wednesday, Australian Marriage Equality directly tackled its opponent's campaign, with Dr Kerryn Phelps telling viewers that "sadly, some are trying to mislead us … by saying it will have a negative impact including on young people".
"The only young people affected by marriage equality are young gay people who, for the first time, will have the same dignity as everyone else in our country and they deserve that," Dr Phelps says in the ad.
But Senator Canavan, who is advocating for a "no" vote, told ABC radio on Thursday he believes changes to education is the "next step" to changing the marriage definition.
"There are not many issues that I get more complaints about at the moment, from mums in particular, than the radical gender reassignment theories that are being increasingly taught in schools," he said.
"We have seen in other countries that this is the next step and to think that we can just change a fundamental institution in our society and not have any other consequences to how we think about things, how things are taught to our children, I think it is naive and that is why we should think twice about things that have stood the test of time."
Education Minister Simon Birmingham slammed the Marriage Coalition ad, which featured three women voicing concerns about what would be taught in their children's schools if there was a change.
One of the claims from Cella White, that her son was told he could "wear a dress next year if he felt like it", was denied by the principal of her son's school, who told Fairfax Media it "never happened".
Mr Birmingham said it was ludicrous to conflate same-sex marriage with anything other than marriage.
"It is patently ridiculous to suggest that allowing same-sex couples to marry is somehow going to see some new wave of teaching reform sweep across the country. That's just not going to happen," he told reporters on Wednesday.
Mr Birmingham, who is voting yes, urged people to think about "the show of love, respect and tolerance" that could come from an affirmative vote.
Senator Canavan did not think that was enough.
"I think in fact what we have is marriage as an institution in our society and many others – it is not just about love, it is more than that – it is this lifelong commitment," he said.
"People fall in and out of love all the time, but it is something that is meant to be there, you are there forever, for your children who have been created from that relationship.
"It is only that relationship and it is only one man and one woman that can create a new child and that is a miraculous event, I think, it is a special event in everyone's lives and I don't think it is all that unreasonable to say we should have a special word and a special institution that cherishes and nourishes that relationship."
The High Court will consider a challenge to the government's same-sex marriage survey next month.