Former Liberal leader Malcolm Turnbull has emerged as the most likely contender for prime minister, as a long-time Abbott supporter gives the strongest hint yet that the nation may soon have a new leader.

Education Minister Christopher Pyne said he can could no longer deny the possibility of a challenge to Prime Minister Tony Abbott early next week.

“I can’t rule it out,” he told Nine Network on Friday morning.

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Mr Pyne also did not deny reports that three cabinet ministers believed a spill motion at the planned party meeting on Tuesday was inevitable.

“Well, I certainly hope so,” he replied when asked if the prime minister would survive, but said he would not be the one to initiate the challenge.

But in a later interview on Sky News, he blamed his earlier comments on tiredness, calling them an “unfortunate misinterpretation”.

A further series of anonymous and unconfirmed leaks have Mr Turnbull firming as the favoured rival.

News Corp has reported that current deputy leader Julie Bishop would happily serve as Turnbull’s second-in-charge, although she has reportedly not ruled out a tilt at the top job in her own right.

Mr Turnbull reportedly confronted Mr Abbott this week about the party’s troubled future.

In the secret meeting on Wednesday evening, Mr Turnbull asked the Prime Minister how he would deal with the current leadership problem and was not satisfied by the response, a Fairfax Media exclusive reported.

Mr Abbott repeated the same themes of his National Press Club address, leaving Mr Turnbull reportedly feeling “underwhelmed”.

But at a community event on Thursday night, the Communications Minister said Mr Abbott had the “utter loyalty” of his frontbench, more so than any other leader history.

Despite calls for him to resign, the prime minister has repeatedly denied he will call a spill, telling Sky News he believed his “friends and colleagues” were not campaigning for his job.

“I trust them,” Mr Abbott said.

Ms Bishop and Mr Turnbull also denied allegations on Twitter they had arranged a meeting in Sydney on Thursday.

Interesting fact – @JulieBishopMP and @TurnbullMalcolm have arranged to meet at his Sydney home today. #auspol

— BenFordham (@BenFordham) February 5, 2015

@BenFordham @TurnbullMalcolm Wrong information!! In Canberra this morning flew to Sydney filmed by @channel9 now with @FionaScottMP

— Julie Bishop (@JulieBishopMP) February 5, 2015

@BenFordham you need to improve yr surveillance! I am on the train to Tuggerah. PoliticsinPub Nth Wyong 2nite pic.twitter.com/vc0VKybUAz — Malcolm Turnbull (@TurnbullMalcolm) February 5, 2015

But the pair will jointly attend a Liberal fundraiser in Sydney over the weekend.

A Fairfax Ipsos poll last week revealed Mr Abbott’s dire approval ratings, with 67 per cent of voters unimpressed with his performance.

Several Liberal backbenchers have since publicly withdrawn their support for Mr Abbott as prime minister.

Western Australian MP Dennis Jensen told News Limited he believed the party couldn’t continue with Mr Abbott as leader.

Speaking on Sky News on Tuesday night, Mal Brough also said Mr Abbott no longer had his “unequivocal support”.

When asked if Mr Abbott would be prime minister next week, former frontbencher Arthur Sinodinos told Sky News on Wednesday: “comrade, ask me next week”.

Christopher Pyne has reportedly called backbenchers in an alleged attempt to better position himself if close ally Mr Abbott is replaced, News Corp has reported.

The education minister reportedly told colleagues deputy leader Ms Bishop has not given the prime minister stronger support because her portfolio of foreign affairs forced her to frequently be overseas, which is being interpreted as a subtle hint that he wants to be promoted to one of her roles if a spill occurs.

Mr Pyne responded to the allegations, telling News Corp he was “firmly of the view” Ms Bishop should remain as deputy prime minister.

—with AAP