Liz Truss's time in No 10 Downing Street was the briefest in history and now the focus has shifted to who comes next.
She was forced to resign after a tumultuous seven days in which she sacked Kwasi Kwarteng as chancellor after just 38 days and dismissed her Home Secretary Suella Braverman a week later.
Making Jeremy Hunt the replacement chancellor appeared to be a good move, well met by the financial sector, but wasn't enough to save her political career.
Sir Graham Brady has said the new prime minister will be in place inside a week.
Here are the main candidates expected to battle it out to replace Ms Truss.
Rishi Sunak
The former chancellor, 42, lost out on the top spot to Ms Truss in the Conservative leadership race.
The bruising campaign saw him repeatedly clash with his rival over economic policies. While Ms Truss said tax cuts would increase investment and fire up the economy, Mr Sunak argued such moves would exacerbate already surging inflation.
After Ms Truss entered office and unveiled £45 billion ($50.3bn) in tax cuts, unleashing chaos on financial markets, Mr Sunak bit his tongue. He steered clear of the Conservative Party conference in Birmingham to allow Ms Truss to “own the moment”.
Mr Sunak is seen by many as a safe pair of hands, having steered the economy through the Covid-19 pandemic with his furlough scheme for workers and help for businesses hit by lockdowns.
Penny Mordaunt
After being knocked out of the Tory leadership race, Ms Mordaunt was appointed leader of the House of Commons and Lord President of the Council by Ms Truss.
The 49-year-old made an impression early on as she played a leading role in the accession council ceremony which saw King Charles III officially declared monarch.
She has held several government roles, including international trade secretary, international development secretary and paymaster general. She was the first woman to hold the posts of defence secretary and armed forces minister.
Ms Mordaunt has come out to defend Ms Truss as Tory MPs express doubt in her policies. She compared the prime minister’s struggles to those faced and overcome by Britain’s wartime leader Sir Winston Churchill.
Boris Johnson
The last prime minister, who was ousted after a succession of his Cabinet ministers resigned, remains a favourite among the party members.
Some closest to him say at the moment he is more interested in making money on the speech circuit than returning to front-line politics. However, the Times reported that Johnson is likely to stand in the Conservative Party leadership contest.
Since Ms Truss succeeded him, he has not directly said he would want to become leader again, but he gave “never say never” answers when questioned before she was appointed.
In a poll of party members — not MPs — this week, Mr Johnson was their favourite to succeed Ms Truss with 32 per cent, Mr Sunak came second on 23 per cent and Defence Secretary Ben Wallace was third on 10 per cent.
About 60 per cent said they would back a proposal of a unity candidate to succeed Ms Truss being chosen without members having a say.
Ben Wallace
The former soldier has served as Defence Secretary since 2019. He retained his position in a Cabinet shuffle after Ms Truss replaced Boris Johnson in September.
The 52-year-old has taken a tough line against Russia following its invasion of Ukraine in February. He has visited Kyiv for high-level talks with the government and repeatedly rebuked President Vladimir Putin over his actions.
When the Russian president threatened to use nuclear weapons against Ukraine, Mr Wallace responded by saying such an outcome was “highly unlikely”.
His position at defence could be in doubt after he insisted the department meets a spending commitment that Mr Hunt may not be happy to authorise.
Suella Braverman
Appointed and then sacked as Home Secretary by Ms Truss, Ms Braverman was made responsible for ensuring the safety of communities in Britain, stopping illegal immigration and tackling crime.
The 42-year-old previously served as attorney general and as a junior Brexit minister.
She was the first Tory MP to launch a bid to succeed Mr Johnson in last summer’s contest. After being knocked out, the former barrister threw her support behind Ms Truss.
Among her pledges is to reform the Modern Slavery Act to make it harder for illegal immigrants to get protection from the law. She said a shake-up would allow UK officials to deport migrants who have “paid tens of thousands of pounds for the privilege of being a so-called modern slave”.
Jeremy Hunt
He said again on Thursday that he does not want to be the prime minister but there were calls for him to put the party and the country first.
Mr Hunt, 55, was called in by Ms Truss to replace Kwasi Kwarteng as chancellor and his emergency steps to tackle the chaos sparked by the mini-budget were generally well received in financial and political circles.
He was appointed health secretary in 2012, taking over responsibility for the National Health Service. During his six-year stint in the post the service suffered plummeting staff morale and worsening patient experience. By 2018 the annual winter crisis had been replaced by “a year-round crisis”, the British Medical Association said.
Mr Hunt was also embroiled in a bitter dispute with junior doctors over pay and working conditions. It led to the first junior doctors’ strike in the UK for more than 40 years.
