Boris Johnson should (if all goes to plan) have been replaced by another Tory MP as leader of the Conservatives by October, at the latest.
But just who could be his successor?
With the last three Conservative prime ministers resigning before the end of their term, it’s going to take quite the individual to step up to the plate.
Ten Tory MPs are in the running right now, most of whom are known for their relationship with the outgoing PM or their political careers.
So here’s a breakdown of the most unusual facts (or gaffes) you might not know about the person who may soon reside in No.10.
Liz Truss: A fan of pork markets
The foreign secretary has made little secret of her leadership ambitions, with a series of high-profile interventions and photo opportunities in which she appeared to be channelling late PM Margaret Thatcher.
Truss is also known for her public slip-ups, having once accidentally sat on fellow minister Sajid Javid’s lap in the Commons.
But her internet fame stems from getting too excited about pork markets.
In 2014, her improbably upbeat speech about opening pork markets in Beijing went viral, and her excitement turned her into a meme which lives on today.
She caused further hilarity when telling the Tory Party conference that year: “We import two-thirds of our cheese, that is a disgrace.”
Rishi Sunak: Coca-Cola addict
The ex-chancellor whose resignation accelerated the exodus of Tory MPs from Johnson’s government, Sunak also famously slipped up in public only last year.
“I’m a coke addict. A total coke addict,” Sunak told two bemused schoolboys, before descending into pit of sheer panic at the realisation of what he has just said.
“Coca-Cola addict! For the record, just to be totally clear, I am a Coca-Cola addict. I have seven fillings to show for it.
“So now...so yeah, exactly, I could get in trouble. So I genuinely do have seven fillings because I got through a lot of the stuff when I was young, so people should not...don’t, don’t, don’t do that.”
Jeremy Hunt: Confused husband
Former cabinet minister Jeremy Hunt has been a persistent backbench critic of Johnson.
But he managed to insult both the Chinese government and his own wife with a gaffe he himself has described as a “terrible mistake” in 2018.
The then-new foreign secretary was making his debut in China when he became momentarily confused about his spouse’s nationality, describing her as “Japanese”.
During a meeting with his counterpart, Chinese foreign minister Wang Yi, he said: “My wife is Japanese – my wife is Chinese. That’s a terrible mistake to make.”
Penny Mordaunt: Crude in the Commons
Mordaunt, who has been described as the “dark horse” of the leadership race, is currently the trade minister.
She is also a Royal Navy Reservist and so has taken part (or been a victim of) her fair share of military frivolity – so her gaffe is less of an error and a bit more, er, deliberate.
She explained what happened in 2014, when she said: “During our mess dinner at the end of the course I was fined for a misdemeanour, and the fine was to say a particular word, the abbreviation of cockerel, several times during a speech on the floor of the House of Commons and mention all of the officer’s names present.”
And here is that speech – maintaining a straight face throughout but very nearly cracking at the mention of “cock-a-hoop” around the 2:36 mark.
She even won a Spectator Speech of the Year award for it but said she felt “a bit of a fraud” because “let’s face it, the reason I won this award is not because of the hours I put in or the carefully crafted speech, it’s because I referred to male genitalia during the course of it”.
Sajid Javid: Proud of his roots
Sajid Javid’s resignation on Tuesday caused chaos in No 10, as the health secretary from famously humble beginnings left the government.
State school-educated Javid – known as “The Saj” in some circles – is the son of a bus driver who arrived in England from Pakistan in the 1960s.
In 2016, Labour’s Sadiq Khan was elected London’s first Muslim mayor in the face of Tory rival Zac Goldsmith campaign, which was trying to paint him as sympathetic to Islamic extremists.
Javid reached across party lines and tweeted his congratulations to Khan, “as one son of a Pakistani bus driver to another”.
Baroness Sayeeda Warsi, former chairman of the Conservative Party, also joined in.
Tom Tugendhat: Afghan war veteran
The chairman of the Foreign Affairs Committee became the first to announce his intention to stand for leader.
Tugendhat, the chairman of the foreign affairs committee who served in Afghanistan as a soldier, said of the fall of the country to the Taliban: “This doesn’t have to be defeat, but at the moment it damn well feels like it.”
Discussing the controversial evacuation of UK troops from the war-torn country last summer, he told the Commons: “Like many veterans this last week has been on that has seen me struggle through anger and grief and rage.
“The feeling of abandonment, of not just a country but the sacrifice that my friends made.
“I’ve watched good men go into the earth, taking with them a part of me, a part of all of us.
“This week has torn open some of those wounds, left them raw, left us all hurting.”
Suella Braverman: Odd leadership bid
Attorney general Suella Braverman launched an unlikely leadership bid as support for Johnson crumbled around him.
On Wednesday, she has turned convention on its head by calling for Johnson to resign as prime minister – but opted to stay in her job at the same time.
The cabinet minister, who has previously been a staunch supporter of the PM, also said she will put her name into the ring if there is a leadership contest.
A Suella Braverman for PM Twitter account has also sprung up, with Tory MP Desmond Swayne becoming the first to tweet his support for her bid.
Nadhim Zahawi: Learned English through UK tabloids
Zahawi, who started off the week as the education secretary before taking Sunak place as chancellor on Tuesday, was one of the final members of the cabinet to publicly call for Johnson to go.
His announcement was particularly surprising, considering 24 hours before he had been trying to steady the ship of government by promising Johnson still had “integrity”.
Zahawi ’s family fled from Iraq to the UK when he was a child, back in 1976. He said he found it “genuinely hard” to fit in initially because of the language barrier.
But, he told the Spectator: “I started reading The Sun and it helped me improve my reading.
“I couldn’t make any sense of the Telegraph because my English wasn’t good enough.”
Grant Shapps: TV host in waiting
The transport secretary has developed a reputation for his PR stunts in recent months, even leading to comparisons with the 2005 political satire The Thick Of It.
Back in January, he produced a whole video just to promote his department’s decision to remove announcements on trains – which people quickly criticised him for.
This wasn’t the last promotional video, either. In April, he went one-step further and used a green screen along with bubbly background music to create a 90s feel to promote ‘The Great British Rail Sale’, which created a similar stir.
Kemi Badenoch: Anti-identity politics
The former equalities minister announced she was throwing her hat into the ring on Friday, vowing to take on “identity politics”.
Badenoch caused a stir last year, during Black History Month, when she suggested schools should not be teaching white privilege as an uncontested fact. She claimed said white children should not be taught about their “inherited racial guilt” and even suggested schools teaching “these elements of policy race theory as fact” are “breaking the law”.
Last year, she was put under pressure to apologise for criticising the journalist Nadine White after she submitted a routine request for comment.
White had asked Badenoch why she hadn’t appeared in one of the government’s Covid vaccines videos which aimed to increase the uptake of vaccine among Black people.
In response, the then-minister tweeted out White’s personal details and dubbed her behaviour “creepy and bizarre” in a Twitter thread. White was forced to lock her Twitter account because of the resulting abuse.