Malcolm Turnbull's backers say he has extended his support base in the face of a possible second challenge from rival Peter Dutton because frontbenchers who voted against the Prime Minister yesterday have now pledged their loyalty.

Key points: Peter Dutton could launch a second challenge as early as today

Peter Dutton could launch a second challenge as early as today Ten frontbenchers offer resignations to Turnbull, two have been accepted

Ten frontbenchers offer resignations to Turnbull, two have been accepted Senior ministers Scott Morrison and Mathias Cormann reiterate support for PM

Mr Turnbull has also won the public backing of two of his most senior colleagues — Senate leader Mathias Cormann and Treasurer Scott Morrison.

Mr Dutton's supporters are confident they can replace Mr Turnbull as leader with another move as early as this week.

But Turnbull loyalists point out some of the 35 people who backed Mr Turnbull yesterday have now publicly and privately supported the PM.

Cabinet ministers Greg Hunt, Michael Keenan and Steve Ciobo, as well as Citizenship Minister Alan Tudge, all offered their resignations after voting for Mr Dutton, but the offers have not been accepted.

Mr Turnbull said he'd had discussions with all of them.

"What I'm endeavouring to do is to obviously ensure that the party is stable, to maintain the stability of the Government of Australia. That's critically important," he said explaining how he was handling their disloyalty.

"And so, the Cabinet ministers, apart from Peter Dutton of course, who came to me and told me that they had voted for Mr Dutton in the leadership ballot, have given me unequivocal assurances of continuing loyalty and support," he said.

Sorry, this video has expired Scott Morrison says Malcolm Turnbull has his full support

During Question Time in Parliament, federal Labor forced Mr Hunt, Mr Keenan, Mr Ciobo and Mr Tudge to pledge their support for Mr Turnbull.

But Mr Dutton and former International development Minister Concetta Fierravanti-Wells have gone to the backbench.

But today, Senator Cormann, whose backing is keeping Mr Turnbull safe for now, declared he would continue to serve him loyally.

"I support Malcolm Turnbull as Prime Minister," the Senate Leader said.

"I was very grateful when Malcolm invited me to serve in his Cabinet in September 2015. I have served Malcolm loyally ever since and I will continue to serve him loyally into the future."

When asked if he could rule out having any leadership ambitions, Mr Morrison put his arm around Mr Turnbull and said: "This is my leader and I am ambitious for him."

Their backing came as Mr Dutton confirmed he was calling his colleagues to keep up his pitch to replace Mr Turnbull as PM.

"I'm speaking to colleagues, I'm not going to beat around the bush with that, mate," Mr Dutton told radio station 3AW this morning.

Prime Minister Malcolm Turnbull could be facing a frontbench reshuffle headache. ( ABC News: Matt Roberts )

PM says leadership 'confirmed'

When asked about Mr Dutton's vow to mount another challenge when confident about his numbers, Mr Turnbull replied:

"We had a ballot earlier this week, as you know. The iron laws of arithmetic confirmed my leadership of the Liberal Party."

Mr Dutton quit the ministry on Tuesday after Mr Turnbull narrowly fended off his leadership challenge by seven votes.

Today he used radio interviews to spell out his policy platforms, including taking the GST off electricity bills for families.

"It would be an automatic reduction of 10 per cent for electricity bills and people would feel that impact straight away," he told Triple M radio.

Mr Turnbull said it would be a very expensive proposal and Mr Morrison said it would cost about $7.5 billion over four years and the Commonwealth would have to reimburse the states for that money.

"That would be an absolute budget blower," Mr Morrison said.

"You can make all sorts of promises about how much money you are going to spend but at the end of the day you have got to account for it."

'They're coming after him'

Mr Dutton was doing the media rounds after a series of late-night resignation offers left Mr Turnbull clinging to power.

Health Minister Greg Hunt offered his resignation but it wasn't accepted. ( ABC News: Matt Roberts )

Earlier, one source close to Mr Dutton indicated another two or three Liberals had drifted to Mr Dutton.

That would leave the new backbencher just four or five votes short of the 42 he needs to seize the leadership.

One of Mr Turnbull's supporters conceded it is close. "They're coming after him," they said.

Trade Minister Steven Ciobo offered to resign. ( ABC News: Ross Nerdal )

Bill Shorten is seeking to capitalise on his opponent's woes, writing to Mr Turnbull and demanding he avoid making any decisions that would "bind an incoming government" until the Liberal leadership is "satisfactorily resolved".

Mr Shorten said actions covered by his request include major policy decisions, significant appointments, major contracts and commitments that may affect international negotiations.

The Prime Minister's strategy to maintain his leadership rests on convincing waverers that a win for Mr Dutton means an early election the party is not prepared for.

"We would be in an election by Friday," one source told the ABC, saying the Coalition would start well behind Labor.

"We ain't got the brass and we're not battle-ready."

Pro-Turnbull forces argue crossbenchers and potentially some Nationals would decline to support a Dutton-led government in a no-confidence motion, which would trigger an early poll.

Queensland Liberal MP Luke Howarth said he believed Mr Turnbull would survive the week, and that the frontbenchers were obliged to resign.

"If they voted for Peter Dutton, that's probably the right thing to do," he said

Sorry, this video has expired Foreign Minister Julie Bishop fronts media with NZ's Deputy PM Winston Peters

Nationals caution against drastic action

Nationals frontbencher Darren Chester has raised the possibility he and some colleagues could move to the crossbench if Mr Dutton wins.

The ABC contacted several Nationals MPs last night but could not find anyone other than Mr Chester contemplating such a move.

Queensland Nationals MP George Christensen advised against the move, saying the Liberal Party's internal functions are not his business.

"When we had our own leadership troubles, I was very affronted at Liberals sticking their bib in internal National Party affairs," he said.

"If that is coming from National Party people then they need to stick their bib out of internal Liberal affairs."

Former Nationals leader Barnaby Joyce dismissed the idea as "silly".

"I think that I will let the Liberal Party look after themselves," he said.