Liberal senator Cory Bernardi has declared he will never vote in favour of same-sex marriage, joining Eric Abetz in warning that some Coalition MPs would not be bound by the results of a national public vote on the issue.

The comments have drawn a rebuke from the government frontbencher Steven Ciobo, who urged colleagues to “think twice before they snub their nose” at the view of the majority of Australians.

The cabinet secretary, Arthur Sinodinos, who is a close ally of Malcolm Turnbull, argued there was no point having a plebiscite if politicians did not take notice of the people’s verdict.

Abetz, Tony Abbott’s former Senate leader, told Guardian Australia it would be up to individual members to decide how to cast their parliamentary vote, contradicting Malcolm Turnbull, who said the people’s verdict in a planned plebiscite would “stick”.



Bernardi, another conservative, said: “There’s no way I’m ever going to cast a vote in favour of changing marriage. I don’t know that I would be expected to do so.”

He said Abetz had been right to raise the issue of how the question put to voters would be worded.

“There are people who are always going to be supportive of changing marriage and people who are always going to be opposed to it and you can’t expect people to cast a vote in favour of something that is against everything they believe in simply because a majority of Australians say that should be the case,” Bernardi said.

“If the Australian people, 51% to 49%, say, ‘Yes, we want to change the Marriage Act,’ maybe it’s incumbent on some of us to say we’re going to represent the 49%.”

The comments have exposed divisions within the Coalition and prompted questions about the point of spending more than $150m on a national vote if the results would not be binding on MPs. Supporters of marriage equality have accused Abbott and his conservative allies of using the proposal for a national vote some time in the next parliamentary term as a stalling tactic.



Ciobo, the minister for international development and the Pacific, said it would be “passing strange” for anyone in politics to ignore the results.

“What I do know is that at the end of the process we’ll have a clear point of view and I think that any politician, any member of parliament would really have to think twice before they snub their nose at the view of the majority of Australians,” he told Sky News on Wednesday.

The north Queensland Liberal MP Warren Entsch, a leading proponent of marriage equality within the Coalition, also told Fairfax Media it would be bizarre to spend so much money on a national vote only to disregard the result.

Sinodinos said Abbott was right to declare in August: “What could be fairer than asking the people to tell us what they think on this and agreeing to be bound by whatever the outcome of that people’s vote is?”

The cabinet secretary told Sky News on Wednesday: “Tony Abbott was right then and he’s right now in that there’s no point having a plebiscite if you don’t take notice of what the people have to say. I respect the right of some of my colleagues for reasons of conscience to depart from that but I think we owe it to the public to have a sincere process in which we consult them and respect the outcome of that process.”

Labor and the Greens argued the positioning showed the parliament should abandon plans for the “divisive” plebiscite and just press ahead with legislating marriage equality.

The opposition leader, Bill Shorten, accused the prime minister of selling out his principles and said taxpayer money should not fund “nasty” campaigns against marriage equality.

“I’m not convinced that we need to spend $160m on an opinion poll merely because Malcolm Turnbull has to implement Tony Abbott’s delaying tactics on marriage equality,” Shorten said.

“If Malcolm Turnbull is too weak to confront the right of his party, Labor will have the parliament vote within 100 days of being elected.”

The shadow attorney general, Mark Dreyfus, said Abetz had “let the cat out of the bag” by admitting some Liberals were not planning to respect the expressed will of the Australian people.

“This absurd notion makes a complete joke of our democratic process and renders a $160m national plebiscite totally pointless,” the Labor MP said.



The Labor MP Terri Butler said the comments showed the plebiscite had been “nothing more than an obstruction tactic”.

The Greens senator Robert Simms said the prime minister should allow a free parliamentary vote as soon as possible.

“It’s ironic that Eric Abetz doesn’t want a conscience vote on the issue of marriage equality but when it comes to implementing the outcome of any plebiscite that’s a different story,” Simms said.

“He wants some sort of veto power if he doesn’t like the outcome. This just demonstrates what a complete nonsense this plebiscite is.”

Turnbull, a supporter of marriage equality, originally argued against Abbott’s “circuit-breaker” policy of a plebiscite after the next election but then promised conservative Liberal colleagues and the Nationals he would keep the policy when he sought the Liberal leadership.



In October Turnbull told the parliament his government would abide by the decision made by the Australian people and anyone arguing otherwise was “not living in the real world”.

“When the Australian people make their decision, that decision will stick,” the prime minister said at the time. “It will be decisive. It will be respected by this government and by this parliament and this nation.”

But Abetz said every MP would “make up his or her mind after the plebiscite is held” based on the views of the relevant electorate, the views of the nation and the personal views of the politician.

“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 said.

Last year Bernardi canvassed at the National Press Club how he would react if a majority of people in a majority of states decided they wanted to redefine marriage.

“Who am I to argue with that, quite frankly?” he said.



He said on Wednesday he stood by that statement and still supported having a plebiscite but said there was a difference between accepting the result and actively casting a vote for a certain position.

Bernardi said he believed most MPs would heed the result, so those who would stand by their positions were unlikely to sway the parliamentary outcome.

The human rights commissioner, Tim Wilson, said people who opposed changing the Marriage Act needed to “get their message straight”.

”As far as I’m concerned if you’re a member of the government which put forward the plebiscite proposal you should accept and be bound by the outcome of that plebiscite,” he told Sky News, adding a caveat that backbenchers who were conscientious objectors could abstain.

The attorney general, George Brandis, is drafting legislation to define the question to be put to a plebiscite, the exemptions that would apply to churches and other organisations, and whether voting would be compulsory. It is expected to go to cabinet, and the Coalition party room, as early as next month.