Scott Morrison was sworn-in on Friday as Australia's 30th prime minister after winning a party leadership contest precipitated by an irretrievable loss of support for his predecessor Malcolm Turnbull within the ruling Liberal Party.

Morrison, 50, who was treasurer in Turnbull's Cabinet, was sworn-in by Governor General Peter Cosgrove in the capital Canberra, with his new deputy, former Minister for Environment and Energy Josh Frydenberg, sworn-in as treasurer.

(Getty/Kyodo)

Turnbull, 63, who had been prime minister since September 2015, had faced growing pressure to step down following a record succession of poor opinion polls, which had fueled concern that the Liberals-led coalition would not be able to hold on to its super-slim majority in the lower house in a general election to be held by next May.

Faced with the bleak opinion poll results, the conservative wing of the party had sought to undermine his support base within the party, culminating in an unsuccessful leadership challenge by Home Affairs Minister Peter Dutton on Tuesday.

Dutton, who subsequently resigned from the Cabinet, sought to claim party leadership again on Friday, only to lose to Morrison in a 45-40 party room vote, according to party whip Nola Marino.

In his first press conference as party leader, Morrison, flanked by his new deputy and treasurer, assured the Australian people that he is working for them.

"There has been a lot of talk this week about whose side people are on in this building. And what Josh and I are here to tell you, as the new generation of Liberal leadership, is that we are on your side."

The new prime minister identified the ongoing drought in Australia as his top priority, followed by maintaining the current strength of the economy. He also singled out health care as an area of interest, saying he was "distressed by the challenge of chronic illness in this country."

Morrison declined to say whether there would be any major shift in economic policy, explaining that he would consider those issues while forming his new Cabinet over the weekend.

There are hopes among Liberal Party lawmakers that Morrison's ascent to premiership will mark an end to a week of open feuding within the party.

Turnbull himself had become the nation's leader in September 2015 after successfully challenging the party leadership of then Prime Minister Tony Abbott.

(File photo of Morrison, left, in 2014)

Earlier Friday, Turnbull, in his final press conference as prime minister, described the week's events as a "determined insurgency" by his political rivals within the party to "bring down my prime ministership."

"Peter Dutton and Tony Abbott and others who chose to deliberately attack the government from within, they did so because they wanted to bring the government down," he said.

Turnbull said he will leave parliament "not before too long," echoing statements he made on Thursday that former prime ministers should not stay in parliament.

Morrison won a three-way contest between Dutton and Foreign Minister Julie Bishop in a vote among party lawmakers earlier on Friday, with Bishop knocked out in the first round of voting.

Frydenberg was named successor to Bishop as deputy party leader.

After the vote, Dutton thanked Turnbull and Bishop for their service and pledged his "absolute loyalty" to Morrison.

Friday's ballot was held after Turnbull received a petition, signed by the majority of party members, to convene a party room meeting, as the prospect of his continuing leadership became increasingly tenuous.

In a press conference on Thursday, Turnbull promised to call a party meeting and allow a leadership challenge to go ahead if he received such a request, while adding that he would not run in the leadership contest.

At Friday's press conference, the outgoing prime minister touted the 11-nation Trans-Pacific Partnership free trade deal as one of his crowning achievements while in office.

Turnbull, along with Japanese Prime Minister Shinzo Abe, was one of the key forces behind bringing the multilateral trade talks to fruition after the United States withdrew from an original 12-member pact.

"When (U.S. President) Donald Trump pulled out of that everyone thought it was dead. I was mocked by some for keeping at it. But we managed to secure the TPP-11," he said.

Leadership challenges have become a common feature in the Australian political landscape in recent years.

No Australian prime minister has served an entire term in office since John Howard in 2007, with six prime ministers serving since.