Conservatives in the Federal Government have warned Liberal MPs trying to break the impasse on same sex marriage they risked "destroying" the Coalition, as internal divisions over the issue widen.

Key points: Warren Entsch has hit out at Queensland LNP president for "intimidating" MPs who support same-sex marriage

Warren Entsch has hit out at Queensland LNP president for "intimidating" MPs who support same-sex marriage Entsch said anonymous threats have been made in the media against those who support change

Entsch said anonymous threats have been made in the media against those who support change A group of Liberals is calling for the Coalition to allow conscience vote on same-sex marriage

On Wednesday morning Queensland Liberal MP Warren Entsch hit out angrily at what he said were "veiled threats" made against Coalition members who wanted to abandon the policy of a plebiscite.

Mr Entsch is one of a group of Liberals calling for the Coalition to allow a conscience vote on the issue when Parliament resumes next week.

But conservatives hit back. Queensland Nationals senator Barry O'Sullivan accused Mr Entsch and other MPs of "quite treasonous" behaviour.

"This is just a smattering of people who are just going to go and go and go until they get want they want … it's completely wrong," Senator O'Sullivan said.

The senator said he was particularly angry about the suggestion some Coalition MPs could cross the floor to interrupt Parliament and bring on a vote on same sex marriage.

"They will destroy the Government in the process," he said.

"This will attack the Prime Minister's authority, it will attack the Government's authority and the confidence the Government can govern."

Senator O'Sullivan said the Coalition had made a "solemn promise" to pursue a plebiscite on same sex marriage, and it would be a "massive breach of trust" to abandon it.

"The majority of their colleagues do not agree with [these MPs] yet they will not abide it… they, in quite a treasonous way, are now prepared to cross the floor to give the governing of the country across to the Opposition to do something completely inconsistent with Government policy."

The former prime minister Tony Abbott also weighed in on the debate, saying any Coalition MPs who crossed the floor on a procedural motion would be betraying voters.

"It's obviously a dramatic loss of discipline inside the Government, it's a serious attack on the authority of the leadership, but at the end of the day it's a breach of faith with the electorate, and I hope they think long and hard before they do that," Mr Abbott said.

'I have every right to be able to express a view'

The Queensland LNP president Gary Spence has also criticised the Coalition MPs who want a vote in Parliament, writing to party members to say he was "disappointed that views that do not accord with the party's policy have been aired publicly".

"I am equally disappointed that members elected under the LNP banner have chosen to take a position that defies LNP policy and the wishes of the LNP's membership," Mr Spence said.

That has infuriated Mr Entsch, who phoned Mr Spence last night and told him he would not be silenced.

"I have every right to be able to express a view," he said.

"I have every right to vote according to my conscience.

"I am not going to be dictated to. If they don't like it — as I said to the president last night — disendorse me.

"I am not making threats, they are the ones making threats against me.

"I just said to him, mate don't threaten me — do it, pull it on, bring it on."

Mr Entsch is also angry because he says anonymous threats have been made in the media against people, including himself, who support changing the law to allow same-sex couples to marry.

He said some people would declare any change to be "the end of the world and we are all the anti-Christ".

MP Warren Entsch says threats have been made against people who support same-sex marriage. ( AAP: Mich Tsikas )

He defended his Liberal colleague Trevor Evans, who has also advocated for same-sex marriage.

"Veiled threats have clearly been made by anonymous sources," he said.

"If you are going to make those sort of threats, put your name to it and have the courage to stand up for what you claim to believe in."

Mr Entsch said he told Mr Spence of his real "disappointment and anger that this was also targeted at first-term members in an effort to intimidate them".

"Members should not be intimidated one way or other in relation to how they do their job," he said.

"They do it as they deem it to be appropriate."

Plebiscite 'remains our policy'

The long-serving Liberal MP declared that the pressure would not work.

"It is not going to distract or deter people that are committed to making this happen," Mr Entsch said.

"We are being honest about this, there has been no surprise. I have been working on this issue now for well over a decade.

"I am proud to say that I am doing it. I am not going to back off on it."

Mr Entsch again rejected the LNP policy which is for a plebiscite, or national ballot.

"If we are going to start this, why on earth have we got a parliament?" he asked.

"We just shut the place down and we do everything by plebiscite. It is just a nonsense."

Senator O'Sullivan said he was not making any direct preselection threats to any of the MPs — but many party members would judge them harshly if they ignored its policies.

"The preselectors will weigh this up — there's no question about that, they do now," he said.

Mr Entsch predicted there would be a robust discussion on the issue in the party room when MPs return to Canberra next week.

Despite Mr Entsch pushing for the conscience vote, Prime Minister Malcolm Turnbull insisted the Coalition remains committed to a plebiscite.

"That is the commitment that we took to the election and that remains our policy," he told Triple M Albany on Tuesday morning.