Mr Dutton will be elected unopposed, former home affairs minister Karen Andrews says.

Ms Andrews was expected to take on the job as deputy but as she and Mr Dutton are both Queensland MPs that was not possible.

"It was important the deputy came from a state other than Queensland and whilst that is personally disappointing for me ... it was untenable to have a leader and a deputy leader from Queensland," she told ABC News on Wednesday.

"I believe very firmly Peter will be elected unopposed as the leader of the Liberal Party. His deputy is almost certain to be Sussan Ley. Together they will have the job of bringing together our team."

Ms Ley is a former environment minister who holds the NSW seat of Farrer.

Finance Minister Katy Gallagher described Mr Dutton as the "last man standing" and dismissed he would be a threat to the Labor government.

"If Peter Dutton is the answer, then it's not entirely clear that they heard the questions that were raised during this election campaign," she told reporters on Wednesday.

Treasurer Jim Chalmers said Mr Dutton's elevation to Liberal leader would demonstrate the party "learned absolutely nothing" from the wipeout on election day.

"Peter Dutton has all of the same core characteristics that people didn't like that they saw in Scott Morrison," Dr Chalmers said.

"We're up for a very divided period when it comes to the Liberals and Nationals."

Meanwhile, former prime minister Scott Morrison had lost credit with voters, who were starting to turn against him last year but the Liberal Party was still right to keep him as leader, an outgoing MP says.

The former Liberal member for the NSW seat of Wentworth, Dave Sharma, ousted by independent Allegra Spender, says voters in his electorate did not believe Mr Morrison or the coalition government was sincere.

"When you spoke to people ... it was almost visceral, their reaction (to Mr Morrison)," Mr Sharma told ABC Radio National.

"Undoubtedly, the (former) prime minister had lost some prestige and credit over the last few years."

The so-called 'teal' candidates like Ms Spender positioned themselves cleverly to voters as an alternative, Mr Sharma said.

But the moderate Liberal said he was not one of the MPs who urged former treasurer Josh Frydenberg - who also lost his seat to 'teal' independent Monique Ryan - to challenge Mr Morrison for the leadership.

In September last year, some Liberal MPs urged Mr Frydenberg to turn against the Liberal leader out of fear he was steering the government to defeat, the Sydney Morning Herald reports.

"My view was, and remains, that we should stick with the leader we've got and take them to the election and if the electorate pronounces a verdict, as it has on this occasion, so be it," Mr Sharma said.

With Mr Morrison stepping down as party leader on election night, there is no better option to take the party forward than Mr Dutton, Mr Sharma said.

"He's our most experienced parliamentarian ... his first job and his main job is to hold the government to account and to be opposition leader," he said.

Australian Associated Press