Liberal deputy Julie Bishop has downplayed the possibility of a Peter Dutton prime ministership, saying a number of people who voted against Malcolm Turnbull have now reconsidered their position.

Ms Bishop also rejected reports she would quit politics to strip the government of a majority should Mr Dutton seize the top job.

"I've never made that threat to anyone," she told ABC radio on Wednesday.

Nine frontbenchers have offered their resignation after Tuesday's leadership ballot, with prime minister accepting that of Mr Dutton and International Development Minister Concetta Fierravanti-Wells.

But the foreign minister said a number had accepted Mr Turnbull's offer to retain their job in the ministry, while other Dutton supporters were now rethinking their votes.

She didn't "envisage" the former home affairs minister becoming prime minister.

"I believe that the prime minister has been endorsed by a majority of the partyroom... and understand that a number of people who didn't vote for him have now said they will back him," she told ABC radio on Wednesday.

Ms Bishop said she was surprised Mr Dutton had challenged Mr Turnbull in Tuesday's partyroom meeting.

"I thought that the interests of the party were to unite behind a set of policies that would be delivered for the Australian people," she later told the Nine Network.

"But everybody has a right to stand if they believe that is in the interests of the party and in the interests of the party and in the interests of the country."

Asked if she would put her hand up if there was another leadership spill, as expected, Ms Bishop said she was not "considering or canvassing any of those options".

"I have a job as foreign minister and the most important job as the member for Curtin, and that is where I am focusing all of my energy and attention," she told Nine.

She also confirmed Finance Minister Mathias Cormann backed Mr Turnbull, after his post-vote silence sparked speculation about who he supported in the ballot.

"Mathias is very busy focusing on implementing the coalition's policies through the Senate, and I understand he is supporting the prime minister and will continue to do so," Ms Bishop told Sky News.