Peter Dutton has vowed to rebuild the Liberal Party as an electoral force after a stunning defeat in the Aston by-election – but the party’s next test could be much sooner than anticipated.

Senior Liberals have told The New Daily that former Prime Minister Scott Morrison’s resignation is expected when Parliament sits again in May, forcing a by-election in the seat of Cook.

That will set up a fresh test for Mr Dutton’s leadership amid a debate about the party’s electoral viability and whether the defeat on Saturday was an image problem confined to Victoria or a much wider indictment on his electability.

Liberal MPs said there was no support building for a change in leadership, but the Opposition Leader is facing calls to present voters with policies and refresh his frontbench to restore a damaged Liberal brand.

Resignation expected

One member of the NSW Liberal state executive, the party’s ultimate decision-making body, said they had been advised Mr Morrison had accepted a job offer and “would resign after the budget”.

Other party power brokers said a poll could even be triggered sooner but another MP said they understood Mr Morrison was still negotiating terms.

TND understands Mr Morrison has been offered a spot on the board of an American organisation but sources declined to go into details and the former PM did not return a request for comment.

A by-election would test the Liberals’ support under Mr Dutton in NSW after he was absent from a state election that drew an 11.9 point swing to Labor in a seat partly overlapping Cook.

Another poor showing would bring fresh questions about the party’s viability and alternative leaders.

One MP said the result in Aston made clear that Mr Dutton would now need to reorder his frontbench to remove MPs with “s–t on their shoes” from the Robodebt scandal and promote new talent.

“We will have to start showing some policy ambition and bring in a few ideas so that it is Peter Dutton’s Liberal Party, not Peter Dutton filling in after Scott Morrison,” they said.

Local issues?

Mr Dutton struck a defiant tone on Sunday morning after a by-election rout and 6.5-point swing to Labor’s Mary Doyle delivered a victory to the government not expected by either party or recorded in a century.

The Opposition Leader had set up the by-election as a test of his leadership and said on Sunday the party had to rebuild and sell its message more effectively, but said the result reflected issues in the state party.

“I have a leadership style, which I believe [my colleagues] appreciate, which is why people very strongly are expressing their support to me,” he said.

“But we have a particular problem in Victoria, there is no question about that.

“Even back to 2013, with all of my predecessors, Victoria is the one state that we have never held a majority of seats in and there are huge issues at a state level as well.”

It was Labor’s best result in a single election contest in Victoria since 1904, Professor of History at ANU, Frank Bongiorno said.

“Victoria is a small ‘l’ liberal state and the Liberal Party egged on by the Murdoch media has moved further and further to the right,” former PM Malcolm Turnbull tweeted.

A row over transgender rights had erupted in the Liberals’ Victorian party room after Victorian Opposition Leader John Pesutto failed to expel Liberal MP Moira Deeming for attending a rally on the issue that also drew neo-Nazi protesters.

A new test

Mr Dutton was also firmly in the frame of Labor’s campaign, which included a last-minute pitch to Aston’s Chinese voters on WeChat, which may have been aimed at concerns about his past criticism of Beijing while defence minister but also his current leadership style.

Dutton was Labor’s target in Aston. Photo: AAP

“He’s the leader of the remnants of Scott Morrison’s faction in the Liberal Party,” the advertisement said.

“The Liberal Party needs someone better than Peter Dutton.”

But in a post-election interview Mr Dutton did not signal any major change to his approach to the Opposition Leader’s job, which critics say has been reflexively negative.

Dr Fan Yang from Deakin University, part of a team of researchers monitoring political communication on Chinese-language social media in Australia, said his hawkish foreign policy stance that drove Chinese voters from the Liberals last May, still perturbed some voters.

“The Chinese community is pretty divided over Liberal politicians and especially Peter Dutton,” she said.

A difficult exit

Mr Morrison has remained in Parliament, in the face of condemnation, to avoid causing a by-election in NSW before last month’s state election.

He would be only the second Australian prime minister to leave office without a parliamentary pension following reforms implemented under John Howard but unlike Mr Turnbull he is not independently wealthy.

But he has also had difficulty securing a local job since damaging revelations about his cabinet emerged; unlike his predecessors, he will not receive a pension.

“Everything went cold after they put the inquiry on,” one Liberal said.

Sources said a lack of options had pushed him into considering the offer of an overseas job.