Rishi Sunak looks set to become Britain's next prime minister after his rival Boris Johnson quit the race, admitting he could no longer unite their party following one of the most turbulent periods in British political history.
Sunak, the 42-year-old former finance minister, could become Britain's third prime minister in less than two months on Monday, tasked with restoring stability to a country reeling from years of political and economic turmoil.
The multi-millionaire former hedge fund boss would be expected to launch deep spending cuts to try to rebuild Britain's fiscal reputation, just as the country slides into a recession, dragged down by the surging cost of energy and food.
"The United Kingdom is a great country but we face a profound economic crisis," Sunak said in a brief statement declaring his candidacy to lead the Conservative Party, and thereby become prime minister.
Britain has been locked in a state of perma-crisis ever since it voted in 2016 to leave the European Union, unleashing a battle at Westminster over the future of the country that remains unresolved to this today.
The latest bout of drama has drawn dismay in foreign capitals and ridicule from the world's press.
Johnson, the face of the Brexit vote, led his party to a landslide victory in 2019, only to be driven out of office less than three years later after a series of scandals. His successor Liz Truss lasted just 44 days before she quit over an economic policy that trashed the country's economic credibility.
Sunak, who has not said how he plans to govern, will inherit a party riven by ideology and with some lawmakers still blaming him for the demise of Johnson after he quit in the summer, triggering a ministerial rebellion.
The withdrawal of the former prime minister late on Sunday also left some ministers and lawmakers feeling angry for looking foolish after they backed him to return to Downing Street, only to have to change course and endorse Sunak hours later.
Sunak could become prime minister if Penny Mordaunt fails to get the backing of 100 lawmakers by 2pm on Monday.
Mordaunt, leader of parliament's House of Commons, has received the backing of around 90 politicians, according to a source in her team. Nearly 190 have backed Sunak, Sky reported.
Should she fail to reach the threshold, Sunak would become prime minister. If she makes it on to the ballot, the party's members - some of whom hold Sunak responsible for bringing down Johnson - will select the winner on Friday.
Finance minister Jeremy Hunt - the fourth in four months - is due to present a budget on October 31 to plug a black hole in the public finances that is expected to have ballooned to up to STG40 billion ($A71 billion).
Investors have at least been given some reassurance that Johnson will not contest the crown.
The former prime minister, who raced home from a holiday in the Caribbean, said on Sunday that while he had sufficient support, he realised he could not govern effectively while the party remained fractured along ideological lines.
"Boris has bottled it," the Metro newspaper said on its front page as many lawmakers questioned whether he had actually secured the backing of 100 lawmakers. By Sunday just over 50 said publicly they would back Johnson.
Sunak came to national attention when, aged 39, he became finance minister under Johnson just as the COVID-19 pandemic hit Britain, developing the successful furlough scheme.
If chosen, the former Goldman Sachs analyst would be the United Kingdom's first prime minister of Indian origin.
After graduating from Oxford University, he went to Stanford University where he met his wife Akshata Murthy, whose father is Indian billionaire N. R. Narayana Murthy, founder of outsourcing giant Infosys Ltd.
© AP 2022