Labor senator Penny Wong is prepared to stand side-by-side with conservative Liberal Senate colleague Cory Bernardi to fight against bestiality being inscribed into law.
Senator Wong made the some-what cynical declaration in an attempt to alleviate Senator Bernardi's concerns legalising same-sex marriage could encourage a push for other relationships to be recognised.
The senators went head-to-head on Wednesday during an anticipated same-sex marriage debate at the National Press Club in Canberra.
The pair represent polar opposites in the debate, which has been gathering momentum in federal parliament with a cross-party bill expected to be tabled next month.
Senator Bernardi, a staunch opponent of same-sex marriage, resigned as parliamentary secretary in 2012 after linking it to bestiality.
"If we redefine marriage it would lead to further calls for redefinition and for other relationship types to be in there," he said on Wednesday.
Senator Wong has previously decried the extreme language used by same-sex marriage opponents and tried to allay their fears stemming from the "slippery slope" argument.
"If you want a statement from me I would stand with you" in defending against bestiality being recognised in law, she said.
"I'm happy to give that today," she said.
Prime Minister Tony Abbott, who hasn't granted his party a conscience vote on gay marriage, has reportedly canvassed holding a national vote to take some heat out of the debate.
Senator Bernardi isn't endorsing a plebiscite but said he'd have to listen to a majority yes vote.
"Who am I to argue with that?" he said.
He will fight "tooth and nail" to stop his party having a conscience vote.
At times the usually silent press club threatened to become rowdy when the occasional jeer bellowed from the audience. But on the whole the debate was respectful.
Senator Bernardi took issue with the term marriage equality, labelling it a "masterpiece of sloganeering" because antidiscrimination laws mean it has no basis in reality.
The "same-sex lobby textbook propaganda campaign" was about "personal desire and self-interest of a vocal minority".
Much of Senator Bernardi's argument focuses on the rights of a child, who he believes shouldn't be deliberately cut off from their biological origins or denied parents of both sexes.
But Senator Wong, who raises her two children with her partner Sophie, says that argument only denies kids with same-sex parents the stability that marriage provides.
"The reality is this, same-sex couples already have children," she said.
In fact, Senator Wong believes it won't change much.
"The sun will rise, heterosexual marriages won't crumble, three-year-olds will still want more ice-cream than is good for them," she said.