Scott Morrison was installed as Australia's seventh prime minister in 11 years on Friday after a stunning Liberal party revolt instigated by hardline conservatives unseated moderate Malcolm Turnbull.

Former home affairs minister Peter Dutton, an ex-police officer and right-winger, was the driving force behind the move to oust Turnbull after a party backlash against his more liberal policies.

But after a torrid week of political intrigue in Canberra, it was Morrison, a Turnbull ally who served as treasurer, who won a party vote 45-40.

Foreign Minister Julie Bishop, another Turnbull backer, was also in the running but was eliminated in the first round of voting.

"My course from here is to provide absolute loyalty to Scott Morrison," Dutton, who Turnbull accused of bullying and intimidation in the move to knife him, said in brief comments afterwards.

Turnbull, who has pledged to quit parliament after his near three-year reign came to an end, survived one attempt to oust him on Tuesday, but ministers then began defecting, throwing the government into crisis.

His departure from politics will spark a by-election for his Sydney seat, threatening the government's wafer-thin one-seat parliamentary majority.

Thwarted ambitions

Dutton, who favours slashing migrant numbers and even pulling Australia out of the Paris climate agreement, was the sole candidate to be prime minister until Thursday when Morrison and Bishop entered the fray to try to halt his power grab.

Former prime minister Tony Abbott, an arch conservative widely seen as the instigator of the move to get rid of Turnbull, said it was now important to "save the government" with national elections due by the middle of next year.

Turnbull must now pay a visit to the Governor-General to officially inform him of events and once there will recommend Morrison to form a new government.

Morrison, an evangelical Christian and former immigration minister, who took credit for "stop the boats" ─ a harsh policy to halt asylum-seekers from entering Australia ─ is further to the right than Turnbull but not as hardline as some in the party.

The unrest is the latest chapter in a turbulent decade for Australian politics, which has frequently descended into manoeuvering and backstabbing that has alienated voters.

No leader has managed to serve out a full term since former Prime Minister John Howard lost the 2007 election, in a remarkable revolving door at Canberra's parliament house.

Dutton needed to prove he had majority backing before launching his tilt at the leadership, or 43 signatures from within the party's parliamentary group ─ a requirement for him to force a second crack at the top job.

Defence Industry Minister Christopher Pyne, another Turnbull ally, blasted disruptive elements inside his party for bringing on the challenge.

"I think some people should have considered the greater good of the people of Australia, and the government, rather than their own self-interest and ambition," he said.

Complicating matters, Dutton was referred to the solicitor-general over his eligibility to sit in parliament due to family financial interests in childcare centres that receive government subsidies ─ a possible breach of constitutional rules.

The nation's top lawyer on Friday cleared him to continue in parliament.

One minister was so disillusioned with the push to oust Turnbull that he took to Twitter to apologise to the Australian people.

"Australia. We owe you an apology. I'm sorry. You deserve better than many of the things our Federal Parliament has served up to you for the past 10 years," wrote Nationals MP Darren Chester, whose party is in coalition with the Liberals.