Opposition Leader Bill Shorten has toughened Labor's stand against a same-sex marriage plebiscite, promising not to let the Turnbull government off the hook in its pursuit for a free vote in Parliament and calling the national vote ridiculous.
Since the election, Mr Shorten has consistently said Labor would consider the terms of the plebiscite when the government finalised its enabling legislation, but in an address to the National Press Club on Wednesday, he said the opposition didn't want to give up on a vote in Parliament.
He questioned how Australians could face fines for not voting in the non-binding plebiscite, expected to be held in February, when a group of right-wing Coalition backbenchers have indicated they won't be guided by the result.
He said that if Labor bowed to the lowest common denominator, things would move on and the vote in Parliament would not go ahead. "I don't want to let the government off the hook on that." he said.
"I think legislating this issue is a far better way than dealing with it in a plebiscite.
"How is it that Australians will be compelled to vote in a plebiscite, which Mr Turnbull's backbench will not be compelled to accept?"
Mr Shorten praised former High Court justice Michael Kirby for his opposition to the plebiscite, arguing it would set a dangerous precedent where MPs avoid making decisions on controversial issues and instead opt for unnecessary and expensive public votes.
He targeted Prime Minister Malcolm Turnbull for agreeing to continue with plans for a plebiscite after toppling Tony Abbott in September 2015.
The plebiscite was engineered by Mr Abbott last year and adopted by Mr Turnbull to satisfy the progressive and conservative wings of the Coalition.
Mr Shorten said his support for a popular vote in 2011 came before there was a majority of MPs in Parliament in support of changing the law, amended by the Howard government with support of Labor under Mark Latham to specify marriage was between one man and one woman.
"Now Malcolm Turnbull knows the right way to go here but he is captive," Mr Shorten said.
"I don't think the plebiscite is approaching the best option on this question. I know the government says you have to let the people decide."
"The real issue is the government will say this is the quickest path to marriage equality but if they really think that, why are we even going through the process?"
The cost of the plebiscite, likely to be above the $160 million cost expected by the government, was "a high price to pay" for Mr Turnbull to remain as Prime Minister.
"Why do the rest of us have to sign up to a deal to keep the leadership of the Liberal Party," Mr Shorten said.
"The only reason the Liberals are contemplating a plebiscite is it's a delaying tactic. That is the only reason."
In December 2013, the High Court overturned an ACT same-sex marriage law and found the federal Parliament had sole responsibility for laws about marriage, including same-sex marriage.
On Tuesday, an Essential poll found 62 per cent of voters support same-sex marriage, while the same number oppose taxpayer money being given to the 'yes' and 'no' campaigns.
A Fairfax-Ipsos poll in July found seven in 10 voters backed a change to the Marriage Act to allow same-sex couples to wed, while 69 per supported a plebiscite over a parliamentary vote.
