With MPs and the leader of the opposition calling for Boris Johnson to resign, speculation about who may take over is rife. Here are some potential runners and riders should the prime minister resign or be forced out.
Despite being a former remainer, the 46-year-old foreign secretary is the darling of the Conservative grassroots, regularly topping the poll of party members carried out by website Conservative Home.
Fans love her rhetoric, which is heavy on liberty, free trade and patriotism, and credit her with signing a slew of post-Brexit trade deals.
She has a carefully honed public image, helped by lavish use of taxpayer-funded government photographers – including recently having herself pictured Margaret Thatcher-style, atop a tank.
The chancellor, 41, was for some time regarded as the frontrunner to replace Johnson but his popularity has slipped of late among the Tory members who will make the final decision.
Sunak is the son of Indian immigrants from east Africa – a doctor and a pharmacist – who sent him to Winchester, the prestigious private school. He worked in the City before entering politics and takes a markedly different economic approach to Johnson, favouring lower taxes and tougher public spending restraint.
Sunak was criticised recently for being in California as businesses were crying out for help when the Omicron coronavirus wave sent restaurant and pub bookings plunging.
The foreign secretary, 55, lost out to Johnson in the 2019 leadership contest by a clear margin but is still regarded as a potential contender if the job falls vacant again.
Returned to the backbenches by Johnson, he has been scrupulously loyal, using his experience as a former health secretary to chair the health select committee.
His South West Surrey constituency is among those being targeted by the Liberal Democrats, who believe traditional Tory “blue wall” voters are turned off by Johnson’s rule-breaking.
By contrast, Hunt would be regarded as a safe pair of hands, though some colleagues fear he lacks political pizzazz.
The home secretary is a controversial figures to many but her right-leaning views and very obviously tough line on immigration make her appealing to many among the Tory membership, as well as to like-minded MPs.
An MP since 2010, Patel, 49, has held a series of ministerial posts but faced a two-year exile from the frontbench after being forced to resign as international development secretary for having unofficial meetings with Israeli officials.
Brought back as home secretary by Johnson, he expended political capital keeping her in the job even after an official report concluded she had bullied officials.
Paradoxically, while she in an immigration hardliner, the fact Patel has overseen a period in which there has been much coverage of unofficial Channel crossings by refugees and migrants could count against her.
The chancellor turned health secretary came a fairly distant fourth in the race to succeed Theresa May but is likely to fancy his chances of doing better this time.
The 52-year-old former investment banker and MP for Bromsgrove since 2010 officially backed remain in the Brexit referendum but is not defined by that, and has a suitably robust Tory ideology which would appeal to many elements of the party, as well as a stirring backstory, growing up above the family shop in Bristol.
Javid left Johnson’s cabinet in spectacular fashion in early 2020 after No 10 tried to impose a team of advisers on him but returned as health secretary in June 2021.
His current role could count against him if there is a sense Javid has been influenced by the public health “blob” over Covid rules that are unpopular among many Tory MPs and party members.
The business secretary, 46, certainly has the free marketeer credentials to appeal to key elements of the Tory party and was a contributor, like Truss, to the 2012 tome Britannia Unchained, a handbook for post-Thatcherite Conservatives.
The first black British Conservative to run his own government department, Kwarteng became an MP in 2010 but did not thrive in the Cameron years, waiting until 2018 for his first junior ministerial post.
The east London-born Eton scholar is known as intelligent but with an occasional tendency to speak without properly thinking such as when, late last year, he suggested the parliamentary standards commissioner, Kathryn Stone, should step down over the case of Owen Paterson.
While his current job as education secretary is Zahawi’s first department-leading cabinet role, his prominence and popularity shot up during his year-long stint as minister for vaccines, overseeing probably the most successful project of the Johnson era.
MP for Stratford-upon-Avon since 2010, Zahawi, 54, has a backstory perhaps more compelling even than Javid’s. Born in Baghdad, he and his Kurdish family fled Saddam Hussein’s rule when he was nine and Zahawi went on to have a private education in London.
The co-founder of polling firm YouGov, Zahawi has also worked extensively in the oil industry, and is one of Westminster’s richest MPs, owning a significant portfolio of properties.