Prime Minister Malcolm Turnbull has committed to a national vote on whether to legalise same-sex marriage after the next election, which is expected to cost about $160 million. His predecessor, Tony Abbott, proposed a plebiscite last year after a bitter debate over a conscience vote inflamed tensions within the Coalition. Federal MP Warren Entsch: "The Prime Minister has not called me. Not at all. His office hasn't called up." Credit:Alex Ellinghausen When asked whether he would bind his MPs to vote "yes" if that was the plebiscite result, Mr Turnbull told Parliament last year that "the consequence of a 'yes' vote in the plebiscite will be that same-sex marriage will be legal in Australia". "When the Australian people make their decision, that decision will stick," he said in October. "It will be decisive. It will be respected by this government and by this Parliament and this nation." But Senator Bernardi told Fairfax Media on Wednesday: "Even if the public voted for [same-sex marriage], I wouldn't vote for it.

"It goes against what I believe in. This is a substantial issue and, in the annals of public policy, you want to be on the record about your views." Not backing off super reforms: former cabinet minister Eric Abetz. Credit:Alex Ellinghausen Senator Bernardi said he still expected Parliament would "respect the views of the Australian people" because not all parliamentarians were as passionate about the issue as he and they would be guided by the plebiscite result. Senator Abetz, a leading opponent of same-sex marriage, earlier said he would reserve his judgment following the plebiscite result. "I would need to determine whether [the plebiscite] really is an accurate reflection [of the national view], whether it is all above board or whether the question is stacked, whether all sides received public funding," he told the Guardian Australia.

"But everyone knows my view is very strongly that a marriage between a man and a woman is the foundational institution for socialising the next generation. And every member of Parliament will make up his or her mind after the plebiscite is held. People will take into account the views of the electorate, the views of the nation and their own personal views. It makes you wonder why we would spend millions of dollars on a plebiscite if you're not going to respect the result. "It would be up to each member to decide whether the plebiscite accurately reflects the views of the Australian people, whether it reflects the views of their electorates and whether it is good or bad public policy in their view. "There will be people in the Parliament who could not support the outcome of a plebiscite whichever way it went." Mr Entsch, who introduced a private member's bill to legalise same-sex marriage last year, said a plebiscite would be a complex and expensive process and that politicians should respect the Australian people's verdict.

When asked about Senator Abetz's comments, Mr Entsch told Fairfax Media, "Given he was part of the decision-making process [on a plebiscite], I find it rather extraordinary. "It makes you wonder why we would spend millions of dollars on a plebiscite if you're not going to respect the result. I find it rather bizarre. "If people make a decision either way we should respect that. "It will be a very brave individual - either in the House of Representatives or the Senate - who seeks to challenge the views of the Australian people." Senator Abetz's comments come as Mr Abbott prepares to address US anti-gay marriage group, the Alliance Defending Freedom, in New York.

Mr Turnbull has defended his right to speak at the event, saying there were "fellow members of the Coalition who have different views, and they are ... entitled to express them". Mr Entsch has been working on the wording for a plebiscite question with Attorney-General George Brandis to be presented to the Coalition party room early this year. Coalition frontbencher Steve Ciobo said it would be "passing strange" for politicians to defy the will of the Australian people. "I think any politician, any member of Parliament, would have to think twice about snubbing their nose at the views of Australians," he told Sky News on Wednesday. Another conservative Liberal MP said he would expect many Coalition MPs, including himself, who oppose same-sex marriage to abstain from a vote if a plebiscite proved successful. This would respect the public's verdict while not forcing MPs to vote against their conscience, he said.

The MP, who asked not to be named, said he was concerned about the process leading up to a plebiscite. "I hope this isn't just something being cooked up by Warren Entsch and George Brandis," he said. "There needs to be broad consultation." Shadow attorney-general Mark Dreyfus said: "Eric Abetz has let the cat out of the bag, admitting the Liberals are not planning to take any notice of the expressed will of the Australian people. This absurd notion makes a complete joke of our democratic process and renders a $160 million national plebiscite totally pointless." Other opponents of same-sex marriage have previously vowed to vote according to the plebiscite. "Certainly I, as somebody who has advocated for all Australians to have a say, clearly I'll be bound by what all Australians have to say," Liberal senator Concetta Fierravanti-Wells said last year.

"I don't believe that the majority view will support [change], but if that's not the case then, of course, I would support that." Follow us on Twitter