A day after Mr Abbott used a National Press Club address to dig in and signal unhappy MPs would have to blast him out of office, while also promising to be more consultative, backbench MPs were in open revolt at the direction of his government.

Late on Tuesday evening, a spokesman for the prime minister said Mr Abbott's position hadn't changed and that he still believed removing a sitting prime minister was madness.

Liberal MP Dennis Jensen became the first MP to publicly call on Mr Abbott to step aside after weeks of leadership speculation and rising panic on the government backbench about the Coalition's dire position.

Foreign Minister Julie Bishop ruled out directly challenging Tony Abbott for the leadership but reserved the right to put up her hand if someone else moved to force him to declare the position vacant and hold a ballot.

Fairfax Media understands Communications Minister Malcolm Turnbull has told colleagues the push for change is being driven by the backbench, not by him but he, like Ms Bishop, is talking with colleagues about the government's political woes.

Just 17 months after he was elected, Liberal MPs were hitting the phones on Tuesday night to consult their colleagues about Mr Abbott's leadership woes.

According to some internal estimates, as many as 30 MPs have indicated their desire for a leadership change, raising the chances that next week's return of parliament could see events move quickly beyond the Prime Minister's control.

Dr Jensen's intervention - which has been followed by damaging public statements from other MPs critical of Mr Abbott's leadership - prompted a senior cabinet minister, Immigration Minister Peter Dutton, to claim the Prime Minister was being "sabotaged" by colleagues.

Dr Jensen told Fairfax Media he had had a text message exchange on December 19 last year with Mr Abbott in which he expressed his concerns about the government's direction.

Mr Abbott had replied, Dr Jensen said, that he had heard the MPs concerns but that "we were moving in the right direction".

However, Dr Jensen said he hadn't "seen evidence of change".

"On 23 January I texted him and said he no longer has my support, three days before Prince Philip," Dr Jensen said.

"I believe in being up front and honest about it."

He dismissed suggestions that the criticism came because he had missed out on a promotion to the frontbench.

"If I had been a good boy and whiled away my time I would probably have been promoted, but I'm in this job to do my best for my constituents and the nation."

The Prime Minister was "a "great war time leader but not a great peace time leader".

He also said he did not know how many other MPs felt the same way but "I know a number feel similarly" but would not say - much like Queensland MP Mal Brough - if he would "pull the trigger" on a leadership challenge.

Queensland Liberal National Party backbencher Warren Entsch told Fairfax Media on Tuesday night he supported a party room ballot as soon as next week when parliament resumes.

"The focus has got to go back to dealing with our many challenges. I'm not discouraging him [Dr Jensen] from expressing a point of view. It [the leadership] needs to be resolved. And I suspect it will be, one or way another."

Mr Entsch stopped short of calling on Mr Abbott to resign, though.

Also on Tuesday night, Mr Brough said Mr Abbott did not have his unequivocal support as he attacked the government's below-inflation pay offer for Australian Defence Force members and proposed change to the government's health policy at an electorate forum.

Former prime minister John Howard would not comment on the leadership ructions engulfing the Liberal Party or on Mr Abbott's future when contacted by Fairfax Media.

"I have no comment to make, thank you for your time," he said.

WA MP Ken Wyatt told Fairfax Media he would wait for the first party room meeting of 2015 before expressing an opinion about Mr Abbott's future as leader.

Queensland MP Bert Van Manen said: "It didn't matter who the leader is, we have to change our systems of engaging with the Australian people".

Asked if Mr Abbott could recover, Mr Van Manen said that was "a really good question. It's been a fairly rapid decline".

Liberal MP Karen McNamara, who holds the marginal seat of Dobell on the NSW central coast, said she agreed with Mr Entsch, saying the current instability "has to be sorted out".

"This is a distraction for people. What we should be doing is getting back to being a good government," she said.

She would not comment when asked directly whether she supported Prime Minister Tony Abbott.

Queensland MP Teresa Gambaro said she would "raise" her "specific concerns" at the party room meeting next Tuesday.

Mr Brough's criticisms came after he confirmed to Fairfax Media on Saturday that he had approached to challenge Mr Abbott.

Mr Brough would almost certainly not be elected prime minister in any ballot but the move could pave the way for Foreign Minister Julie Bishop, Communications Minister Malcolm Turnbull or Social Services Minister Scott Morrison to seize the top job.

In a bid to end days of damaging speculation, Ms Bishop assured the Prime Minister on Tuesday she had not been campaigning for his job and had not phoned backbenchers seeking their support or been counting any numbers.

The deputy Liberal leader's commitment not to challenge does not rule her out from running if a leadership ballot is declared and all positions are open.

Mr Dutton sprang to Mr Abbott's defence on the ABC's 7.30 program on Tuesday night and said the Prime Minister was being "sabotaged".

"I sat in Parliament through the Rudd/Gillard/Rudd years and I don't want our party to go through that. I want the PM halfway through his first term, elected by the public, to have a fair go," he said, echoing Mr Abbott's Press Club address.

"Julie Bishop, Malcolm Turnbull and Scott Morrison have been very clear in their support of the PM and I think people going out to sabotage the PM so that he can't get out a clear message just is outside the bounds of what the what Australians see as a fair go."

With Mark Kenny, Latika Bourke, Heath Aston, Judith Ireland