Same-sex marriage could lead to legal polyamorous unions, says Eric Abetz

Senior Abbott government minister Eric Abetz has suggested legalising same-sex marriage could open a “Pandora’s box” of legalising other unions, including polyamory.

Abetz, the leader of the government in the Senate, warned against embracing “the latest fad” as part of a conservative pushback against some Liberal party colleagues who want to bring forward a multi-party bill to achieve marriage equality next month.

Government whip Andrew Nikolic also denied momentum was building for Liberal MPs to be granted a free vote on the issue, and said colleagues who thought same-sex marriage should take priority over economic and national security issues had “rocks in their head”.

Tony Abbott showed no sign on Thursday that he was willing to allow the debate to progress, saying he wanted the government to “remain absolutely focused” on jobs, the economy, and national security.

The prime minister said same-sex marriage was “an important issue upon which decent people can differ”, but he did not agree that it was the biggest talking point in politics at present.

But Liberal moderates supportive of marriage equality warn the government faces not only continuing internal discord but also significant political risk if it does not deal with the issue before facing voters at the next election.

One Coalition MP observed it would be madness electorally to go to the next election effectively telling voters that if they wanted to see marriage equality they needed to vote Labor. Opinion polls put public support for same-sex marriage in Australia at about 70%.

Abetz called on frontbench colleagues to take “the honourable course of action” and quit their leadership positions if they were unable to support the Liberal party’s “long-established policy” of upholding marriage between a man and a woman. And he suggested the change would trigger subsequent calls to allow marriages between three or more people.

“To try to change the definition now will open a Pandora’s box because if you undo the institution of marriage by redefining it for the latest movement or the latest fad you will open a Pandora’s box for all sorts of other potential possibilities,” he told Sky News on Thursday.

Asked to be specific, Abetz said: “Polyamory, clearly – well, polyamory is one of those. That has now been promoted not only to Australian Senate committees but it has been commented on and pursued in Holland, in Scandinavia, in the United States, so let’s not be under any illusion that once you start unpicking the definition of marriage there will be other consequences.”

The interviewer, Kieran Gilbert, said: “So you’re suggesting that it would be legalising multiple spouses, is that what you’re suggesting, that that’s a prospect?”

Abetz replied: “No, no, no, no; look, don’t try and verbal me. What I said was that if you undo the definition you then open up a Pandora’s box and if you say that it is no longer an institution between one man and one woman you then do open up a Pandora’s box.

“Indeed, dissenting judges in the United States and elsewhere have referred to that possibility, so what I am saying is not something new. It is something that many people around the world have said and we have in fact witnessed it.”

It is not the first time opponents of same-sex marriage have invoked the “slippery slope” argument that further changes would be demanded down the track.

South Australian Liberal senator Cory Bernardi lost his job as Abbott’s parliamentary secretary in 2012 over comments that redefining marriage could lead to calls for group marriage and acceptance of bestiality.

Abetz himself told the Senate in 2012: “If the same-sex disqualification is to be addressed as discriminatory, it begs the question: can it be asserted that the other disqualifications are also inherently discriminatory and indicative of ageism, family phobia or polyamorous phobia?”

The growing global momentum for same-sex marriage – fuelled by decisions in Ireland and the US – has prompted supporters within the Liberal party to push ahead with plans for legislation in collaboration with Labor, Greens and independent MPs.

Liberal MPs Warren Entsch and Teresa Gambaro are involved in the multi party efforts to present a private member’s bill after the winter parliamentary recess ends in August. But after reports on Wednesday of a detailed timeframe for the Liberal party room to consider a free vote, conservative elements in the party hit the airwaves to hose down expectations of a breakthrough.

Abbott also played down talk of the matter even reaching the party room, saying it was rare for private member’s bills to proceed to a vote in the lower house – a criterion for the Coalition joint party room to consider its stance on legislation. Before the 2013 election, Abbott said marriage policy would be a matter for the party room to decide.

The Labor leader, Bill Shorten, who proposed his own marriage equality bill a month ago, said he did not care who brought the legislation to parliament “as long as all of us get a chance to have a free vote on the issue”.

Shorten said he respected Abbott’s long-held view about marriage, but hoped the prime minister could put his personal opinion aside and offer his party room a free vote.

“I thank the Liberals who have shown the courage to speak up and sign this [cross-party] bill. I’m conscious their actions carried risks and I thank them for standing by their principles,” Shorten said.

Several ministers, assistant ministers and parliamentary secretaries – including Malcolm Turnbull, Simon Birmingham, Josh Frydenberg and Kelly O’Dwyer – have publicly supported same-sex marriage.

Abbott did not say on Thursday whether frontbenchers should resign if they supported same-sex marriage. The prime minister said there were a range of views within the community, which extended to the parliament and political parties.

Abetz said while Liberal backbenchers were entitled to cross the floor in parliamentary votes, “if you’re a frontbencher you do need to support the existing policy and if you don’t you then resign your frontbench position”.

He also suggested it was the “Asian century”, yet Asian countries had not embraced same-sex marriage.

When Gilbert questioned the comparison, given Australia also differed from many Asian countries on the issue of capital punishment, Abetz accused the media of championing the cause of same-sex marriage rather than allowing “a proper, appropriate debate”.

Abetz added: “I detect that the Australian people are getting a bit sick and tired of the one-way traffic that is being promoted by Australia’s media.”

The independent MP Andrew Wilkie, who is backing the cross-party push, said he did not believe Abetz’s argument about Asian countries made sense.

“Let’s look at other developed countries. New Zealand allows same-sex marriage, the Irish overwhelmingly voted recently to allow same-sex marriage, the United States supreme court just in recent days agreed that same-sex marriage is constitutional,” Wilkie said.

“In countries that are very similar to our country they have come to understand that to not allow same-sex marriage is legislative discrimination and needs to be ended.”

Wilkie said Abbott should be “a man of his word” and fulfil his election promise to let the party room decide on the issue of a free vote. He reminded people the Marriage Act was changed relatively recently – 2004 – to explicitly preclude same-sex marriage in Australia.