Former Treasury chief Rishi Sunak was set to become Britain's next prime minister after the governing Conservative Party chose him as its leader on Monday in the hope that he will be a safe pair of hands to guide the country at a time of economic and political turbulence.

The victory marked a historic moment for Britain: Sunak, who is from the UK's large South Asian community, will be the country's first prime minister of colour.

The new Conservative Party leader and Britain's latest prime minister Rishi Sunak. Photo / AP

But the challenges facing the third prime minister this year are enormous: He must try to shore up an economy sliding toward recession and reeling after his predecessor's brief, disastrous experiment in libertarian economics, while also attempting to unite a demoralized and divided party that trails far behind the opposition in opinion polls.

In his first public statement, Sunak said "the United Kingdom is a great country, but there is no doubt we face a profound economic challenge."

"We now need stability and unity, and I will make it my utmost priority to bring our party and our country together," he said.

But it was the wooden way in which he delivered the speech which led to criticism mere hours into his tenure as leader.

Natasha Clark, chief political correspondent at The Sun newspaper, branded Sunak "Robot Rishi" and said his speech was "very static".

John Stevens, political editor at the Daily Mirror, called the new PM "The Rishbot".

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And Alastair Campbell, former spin doctor for Tony Blair, simply said: "Is that it?"

But he had one fan in broadcaster and former newspaper editor Piers Morgan who said Sunak's speech was "perfect".

Sunak takes over from Liz Truss, who quit last week after 45 tumultuous days in office. His only remaining rival, Penny Mordaunt, conceded and withdrew after failing to reach the nomination threshold of 100 Conservative lawmakers needed to stay in the race.

Sunak will now be asked by King Charles III to form a government and will become the prime minister in a handover of power from Truss, likely on Tuesday.

Liz Truss, right, and Rishi Sunak on stage after a Conservative leadership election hustings at Wembley Arena on August 31. Truss would go on to win that election but only lasted 45 days. Photo / AP

Victory is vindication for Sunak, who lost out to Truss in the Conservative election to replace former Prime Minister Boris Johnson over the summer when party members chose her tax-cutting boosterism over his warnings that inflation must be tamed. Truss conceded last week that she could not deliver on her plans — but only after her attempts triggered market chaos and worsened inflation at a time when millions of Britons were already struggling with soaring borrowing costs and energy and food prices.

The party is now desperate for someone to right the ship after months of chaos — both during Truss' short term and at the end of Johnson's.

As finance minister, Sunak steered the economy through the coronavirus pandemic, winning praise for his financial support for laid-off workers and shuttered businesses.

But he faces the even bigger challenge now of calming markets and trying to tame inflation in Truss' wake. Treasury chief Jeremy Hunt, appointed by Truss 10 days ago, is due to make an emergency budget statement October 31 — if Sunak keeps him in the job.

Britain also faces broader economic problems stemming from the pandemic, the war in Ukraine and the country's exit from the European Union in 2020. Sunak was a firm supporter of Brexit.

Conservative Party leadership candidate Penny Mordaunt, left, and Andrea Leadsom arrive at the BBC studios, in London on Sunday. Mordaunt dropped out of the race. Photo / AP

Tim Bale, professor of politics at Queen Mary University of London, said Sunak's government faces a long list of challenges: weakened public finances, a worsening economic outlook and a wave of strikes amid record-high inflation. Bale called Sunak "rather more competent" than Truss, but said the Conservative Party was "by no means out of the woods yet."

Sunak — who will also be the UK's first Hindu prime minister and, at 42, the youngest for 200 years — was cheered wildly by Conservative lawmakers during a packed private meeting in Parliament minutes after he won the contest on Monday.

Former Cabinet minister Chris Grayling said Sunak had urged the party "to unite and fix the problems the country faces" and had got "a rapturous reception."

Therese Coffey, who was Truss' deputy prime minister, said the whole party should support Sunak now.

"We need to get behind him," she said.

But Sunak still faces resentment from supporters of Johnson for quitting the government in July, a move that helped topple the then-leader. His background as an investment banker at Goldman Sachs and his wife's vast wealth — she is the daughter of an Indian billionaire — also fuel a sense he is out of touch with the struggles of ordinary people.

He take the reins after a chaotic few weeks. Truss' proposal for aggressive tax cuts that would be paid for through government borrowing pummeled the value of the pound, drove up the cost of government borrowing and home mortgages, and forced emergency Bank of England intervention. Truss executed a series of U-turns and replaced her Treasury chief but faced rebellion from lawmakers in her party that obliterated her authority.

In the lighting-quick contest to replace her, Sunak's position strengthened after Johnson dramatically quit the race on Sunday night, ending a short-lived, high-profile attempt to return to the prime minister's job he was ousted from little more than three months ago amid ethics scandals.

Members of the public look through the gates at Downing Street in London as Rishi Sunak was announced as new Conservative Party leader. Photo / AP

The prospect of a return by Johnson had thrown the already divided Conservative Party into further turmoil. He led the party to a thumping election victory in 2019, but his premiership was clouded by scandals over money and ethics that eventually became too much for the party to bear.

He threw in the towel late Sunday despite insisting he was "well placed to deliver a Conservative victory" in the next national election, due by 2024.

The Conservative Party turmoil is fueling demands for a national election. Under Britain's parliamentary system, there does not need to be one until the end of 2024, though the government has the power to call one sooner.

Currently that looks unlikely. Opinion polls say an election would spell disaster for the Conservatives, with the left-of-center Labour Party winning a large majority.
Bale, the politics professor, said the Conservatives are still in trouble even after choosing Sunak.

"And certainly I think voters, while possibly they may give Rishi Sunak a little bit of a bounce, a little bit of credit for not being Liz Truss, are certainly out of love with the Conservative Party as a whole," he said. "So I don't expect this to make an enormous amount of difference to the opinion polls."

- AP