Tony Abbott’s gay marriage stance has been slammed by Labor leader Bill Shorten and leadership rival Malcolm Turnbull after he quashed a free-vote on the matter, only to push a plebiscite.

Mr Shorten said Tony Abbott had left millions of Australians “bitterly disappointed” by denying a free Coalition vote on gay marriage, and that the prime minister was a “dinosaur”.

Then, long-time same-sex marriage supporter Mr Turnbull said he too supports a free-vote on the matter, and feels a plebiscite after the election on gay marriage would dominate debate of other issues for too long.

• Abbott admits ‘captain’s call’ on marriage equality
• Julie Bishop helped quash free vote
• No free vote on gay marriage 

Mr Abbott has come under fire for including Nationals MPs in the Liberal party room debate on same-sex marriage, which meant the pro-gay-union voices were outnumbered, a move slammed by MPs like Christopher Pyne. 

A plebiscite will mean “this issue is a live issue all the way up to the next election,” Mr Turnbull said. “I want to be clear. I think it is an important issue.”

Bill Shorten says Abbott is proving just how stuck in the past he is. Photo: AAP

“But I would prefer between now and the election, the more time I can talk about the economy, about jobs, about innovation, about digital technology and digital efficiency, the happier I’ll be.”

The Opposition leader was similarly opposed to the outcome that looks to have emerged from the Coalition party room.

“Frankly, I’m surprised at why some in the government are so obsessed about stopping marriage equality,” Mr Shorten told Channel Seven.

He questioned the logic of relying on a future referendum, and said the Liberal Party had “squibbed” an opportunity to keep step with voters.

“We shouldn’t have to wait for a referendum, which by the way will cost tens of millions of dollars, I think Mr Abbott just needs to move with the times,” Mr Shorten said.

Last night, government MP Warren Entsch was given approval to put forward a bill to legalise same-sex marriage on Monday, with support from Labor backbencher Terri Butler.

Ms Butler said the Coalition party room vote would not stop the campaign to legalise same sex marriage from continuing.

“There’s no point throwing your hands up in the air and saying the Prime Minister’s a dinosaur so we should all give up,” she said.

The Coalition vote has stoked tensions between politicians over the issue.

This morning Mr Abbott said it was Coalition policy that: “If a frontbencher cannot support the party’s policy, that person has to leave the frontbench”.

That was on show when Labor same-sex marriage advocate Penny Wong barely acknowledged Treasurer Joe Hockey’s greeting as the pair crossed paths in the parliamentary press gallery this morning.

– with ABC