Malcolm Turnbull is still prime minister for now, but Peter Dutton and Scott Morrison are preparing to fight it out if a Liberal leadership challenge is called.
Mr Turnbull set a midday on Friday deadline for the second spill motion of the week, but he's forcing Liberals who want him gone to reveal themselves.
On Thursday he demanded Mr Dutton get at least 43 signatures to force a leadership spill - and promised to quit as prime minister if it goes ahead.
That would open the door for Mr Dutton and Mr Morrison to battle it out.
But Mr Turnbull has warned Mr Dutton he better be eligible to sit in parliament after questions were raised about his financial interests in childcare centres.
"Australians will be rightly appalled by what they're witnessing in their nation's parliament today and in the course of this week," Mr Turnbull told reporters in Canberra on Thursday.
"The reality is that a minority in the party room, supported by others outside the parliament, have sought to bully, intimidate others into making this change of leadership that they're seeking."
The prime minister has lost 13 ministers, including loyalist Mathias Cormann, after they told him the numbers had moved behind Mr Dutton.
"I can't ignore the fact that a majority of colleagues in the Liberal Party party room are of the view that there should be a change," Senator Cormann told reporters, adding it came with a "heavy heart".
Mr Turnbull expects the solicitor-general to provide MPs with advice on whether Mr Dutton is eligible to sit in parliament before Friday's meeting.
The former home affairs minister has his own legal advice that his interest in childcare centres - which receive funding from the federal government - does not breach section 44 of the constitution.
The section bans from parliament anyone who has "any direct or indirect pecuniary interest with the public service of the commonwealth".
"This is a very, very significant point," Mr Turnbull said, having battled through the MP citizenship saga.
"I cannot underline too much how important it is that anyone who seeks to be prime minister of Australia is eligible to be a member of parliament."
Mr Turnbull said the public would be "crying out for an election" once the dust settled.
He said a "form of madness" had taken over those agitating for a leadership change.
Mr Dutton is also facing a Senate inquiry over his decision to give visas to two au pairs in 2015 after Labor referred the matter to a committee on Thursday.
The inquiry will look into allegations concerning the inappropriate exercise of ministerial powers and report by September 11.
Australian Associated Press
