Scott Morrison will be sworn in as Australia’s 30th prime minister this afternoon after beating former home affairs minister Peter Dutton by 45 votes to 40 in a party room spill.

Mr Morrison emerged from Friday’s long-awaited party room meeting as the new leader of the Liberal Party, after winning a leadership spill also contested by former deputy leader Julie Bishop.

His victory was announced by party whip Nola Marino at 1pm (AEST) on Friday. Malcolm Turnbull did not put his name forward for the leadership.

Josh Frydenberg will be Mr Morrison’s deputy. Ms Marino said he had been elected by “an absolute majority”.

Mr Morrison’s victory was something of an upset after a tumultuous few days for the Liberal Party that began with a leadership contest on Tuesday between Mr Turnbull and Mr Dutton.

Mr Turnbull won that vote, but Mr Dutton confirmed on Wednesday he intended to firm up the numbers for another shot at the top job.

Mr Morrison emerged as a potential candidate on Thursday.

Former deputy leader Julie Bishop also put up her hand as a potential leader on Friday. She was the first candidate eliminated, with the fewest votes in the first round.

Mr Morrison emerged from the party room at 1.20pm, alongside Mr Frydenberg. To the clamouring media, he said only: “Save it for later on.”

A few minutes earlier, Mr Dutton congratulated his new party leader.

“I am to provide loyalty to Scott Morrison, make sure we win the election and we beat Bill Shorten,” he said.

Outside the party room, former prime minister Tony Abbott said the government already had “wonderful achievements”.

“There is a government to save,” he said. “That’s what all of us will do our best to do now, to save the government.

Greg Hunt, who stood unsuccessfully for the deputy’s position, said he welcomed a “new generation of leadership” for the Liberals.

“The line has been drawn under a decade,” he said. “This is a moment of unity for the party.”

Mr Turnbull held a final media conference as prime minister at 2pm to confirm that he will quit parliament “not before too long”. That will spark a by-election in his Sydney seat of Wentworth.