Nick Xenophon has confirmed his party will vote against the legislation to enable a same-sex marriage plebiscite, leaving the Coalition to seek Labor’s support in the Senate or face the possible demise of the public vote.

The Greens have already confirmed they will also vote against the bill, and the Nick Xenophon Team (NXT) announcement ensures the Government cannot secure enough crossbench support.

In a statement, Senator Xenophon detailed his party’s position, held by all three senators, to vote against the bill to set up a plebiscite.

Instead they will advocate for a free vote on directly legalising same-sex marriage through an act of Parliament.

“This is a matter that the Parliament can and should decide on as a free vote of all members and senators,” he said.

“In our representative democracy we are paid to make decisions on behalf of Australians who have voted us into office. This is a decision the Parliament should make now.

“The plebiscite, which in any event could be disregarded by the Parliament, could be in the order of $160 million or more.

“We believe this money could be better spent.”

The Opposition will now essentially decide whether to kill off the plebiscite.

Shorten seeking vote in Parliament

Opposition Leader Bill Shorten addressed his party room this morning, continuing to play his cards close to his chest but signalling continuing concerns.

“This is a decision the Parliament should make now.” Photo: AAP.

“There are many problems with the plebiscite,” he told MPs and senators.

“Not least of which is that Mr Turnbull’s been vetoed from even using the words ‘marriage equality’ in the plebiscite by his own right wing.

“The quickest path to resolving this issue would be a vote in the Parliament and that’s what we will be seeking to do in the coming days and weeks.”

Earlier, Labor senator Penny Wong told the ABC that Labor still had “deep concerns” over the plebiscite, saying pressure needed to be applied to the Coalition over the issue.

“The plebiscite is a political deceit imposed upon the Coalition by Tony Abbott and the conservatives,” she said.

North Queensland Liberal National MP Warren Entsch has been a leading advocate within the Government for same-sex marriage to be legalised.

Warren Entsch wants the plebiscite to put an end to the “nonsense”. Photo: AAP.

He said Prime Minister Malcolm Turnbull did not have the option of holding a vote in Parliament.

“As soon as we do that, your mob in the media and of course the Labor Party will be all over him, attacking him for doing a backflip,” he said.

“If this is lost, if this sort of nonsense continues, there’s a high probability that this will be argued over the next three years of government and it will come up again to the next election.

Mr Entsch last year introduced a private members bill to legalise same-sex marriage, co-sponsored by Labor’s Terri Butler.