Peter Dutton says a former solicitor-general has advised him he is eligible to sit as a member of parliament, putting to rest "spurious and unsubstantiated allegations" about his eligibility.
Late on Thursday Mr Dutton tweeted a three-page document signed by David Bennett QC that states the opinion that Mr Dutton is "not rendered ineligible" by section 44 of the constitution.
"Today I received advice from former SG David Bennett AC QC which clearly states I am eligible to sit as a Member of Parliament," Mr Dutton tweeted.
"Mr Bennett was successful in the High Court in Re Canavan and provided advice to Malcolm Turnbull on the eligibility of Justine Keay, Susan Lamb & Rebekha Sharkie, later confirmed by the High Court," he continued.
"...Mr Bennett's unequivocal advice puts to rest the spurious & unsubstantiated allegations raised against by (sic) eligibility."
Mr Dutton is gunning to replace Malcolm Turnbull as prime minister but has been facing questions over his interest in two Brisbane childcare centres through his family's RHT Family Trust.
From July this year, childcare centres receive a direct subsidy from the federal government, raising questions as to whether Mr Dutton could be under a constitutional cloud.
Section 44 of the constitution bans people from parliament who have "any direct or indirect pecuniary interest with the public service of the commonwealth".
Mr Dutton initially relied on legal advice from December 2017 to say he was eligible, but his lawyer Guy Reynolds then updated the advice to include the recent law changes.
Mr Turnbull is awaiting advice from the current solicitor-general on the issue, and says it needs to be seen by Liberal MPs before another leadership spill.
Mr Turnbull said if the solicitor-general's advice cleared Mr Dutton on Friday morning, there could be a partyroom meeting and a spill motion, but he also wants to see the letter purportedly signed by 43 Liberal MPs calling for the meeting - to be held at noon.
"You can imagine the consequences of having a prime minister whose actions and decisions are questionable because of the issue of eligibility," the prime minister told reporters in Canberra on Thursday.
Labor MP Tony Burke moved a motion on Thursday to refer the matter to the Court of Disputed Returns, which if proven could have led to Mr Dutton being disqualified from parliament.
The lower house vote was narrowly lost 68-69.
Mr Dutton queried why the story came out as he was challenging the prime minister.
"The timing on the eve of current events in Australian politics is curious," he said in a statement.
"There has never been any doubt about my eligibility to sit in the parliament and I attach the unequivocal legal advice I obtained in 2017 to that effect."
Former finance minister and close friend Mathias Cormann believes Mr Dutton has nothing to worry about, backing him as the best person to lead the Liberal Party.
"Peter Dutton is a validly elected member of parliament - that's a distraction," Senator Cormann said.
