Defiant Australian Prime Minister Malcolm Turnbull vowed not to "give in to bullies" Thursday in the face of a new leadership challenge, but said he will quit politics if his party no longer supports him.
Former home affairs minister Peter Dutton, an ex-police officer and right-wing conservative, said he was confident he now had the numbers to unseat Turnbull, considered a moderate.
And with senior ministers defecting, Turnbull's near three-year grip on power is tenuous despite surviving a snap ballot on his leadership on Tuesday, winning the vote 48-35.
He said Dutton had yet to prove he has majority backing from the Liberal Party -- a requirement for him to force another meeting to have a second crack at the top job ahead of national elections due by mid-2019.
If a petition arrives showing that support -- and reports late in the day said Dutton was closing in on his target -- the meeting will be held at midday on Friday (0200 GMT).
Turnbull said that if that happens, he will not stand as a leadership candidate and will leave parliament, sparking a by-election which could be problematic for the government which has a wafer-thin one-seat parliamentary majority.
In a twist to the plot, ABC and Sky News reported that Treasurer Scott Morrison and Foreign Minister Julie Bishop, both Turnbull allies, may also stand in a leadership ballot, in a bid to derail Dutton's power grab.
Turnbull accused Dutton and his supporters of intimidation in a crisis that snowballed from Monday after months of poor opinion polls and a revolt by fellow Liberal politicians over plans to embed carbon emissions targets in law.
"What began as a minority has by a process of intimidation persuaded people that the only way to stop the insurgency is to give in to it," he said.
"I do not believe in that. I have never done that. I have never given in to bullies, but you can imagine the pressure it's put people under."
He added that what Australia was witnessing was "a very deliberate effort to pull the Liberal Party further to the right".
Dutton earlier told reporters he had advised Turnbull by phone that "it was my judgement that the majority of the party room no longer supported his leadership".
"As such, I asked him to convene a meeting of the Liberal Party at which I would challenge for the leadership of the parliamentary Liberal Party," he added.
In a major blow, Turnbull's influential Finance Minister Mathias Cormann, along with the employment and education ministers, then said he no longer had their backing.
They joined at least 10 other ministers who have either resigned or offered to.
- 'Absolute crap' -
Complicating matters, it emerged that Dutton faces questions over his eligibility to sit in parliament, due to financial interests in childcare centres that receive government subsidies -- a possible breach of constitutional rules.
"This issue of eligibility is critically important," Turnbull said, adding that the solicitor-general was looking into the matter.
Dutton, described by supporters as a pragmatic legislator who gets things done and by detractors as a racist who demonises refugees, said he has legal advice that he is in the clear.
He quit his cabinet position after his first failed leadership bid on Tuesday and has said that if he became prime minister, he would focus on cutting immigration to ease population pressures and boosting water investment to help drought-stricken farmers.
Dutton and his camp, including former prime minister Tony Abbott who once described climate change as "absolute crap", have also made clear that keeping power prices down was more important than meeting Canberra's commitment to slash carbon emissions by 26 percent by 2030.
The unrest is the latest chapter in a turbulent decade for Australian politics, with no leader managing to serve out a full term since John Howard lost the 2007 election.
And it has played into the hands of the Labor opposition, which has been making the most of it.
"Another day and another one of chaos from this government -- a government that has effectively stopped governing because it's too busy fighting itself," said deputy opposition leader Tanya Plibersek.