Once-loyal MPs such as Will Quince, Sally-Ann Hart and Jonathan Gullis also turned on the PM, weeks after voting for him.
Mr Johnson has stuck it out before and with most of his other Cabinet ministers loyally backing him, he could try to stay.
But if he is forced to resign, or he’s sacked, what happens next, and who could take over?
Here’s everything you need to know…
What is next for Boris Johnson?
If Boris Johnson resigns as Prime Minister before a successor is chosen, the Cabinet Manual says it is “for the party or parties in government to identify who can be chosen as the successor”.
This suggests Deputy Prime Minister Dominic Raab—who stood in for Mr Johnson when he had Covid—or someone else senior, could take the role temporarily.
However, it’s more likely that the current Prime Minister, Boris Johnson, will stay on as a caretaker, or “lame duck” until his successor is chosen.
What’s the process if he resigns?
Tory MPs and members hold a leadership contest to choose a new leader—and therefore the new Prime Minister, without an election. This happened in 2019 when Theresa May resigned.
The exact rules of each Tory leadership contest vary, but, there are two stages and the entire process takes a couple of months.
First, Tory MPs cut the field down into two sets of candidates, allowing factions of MPs to choose the shortlist to keep extreme candidates off the ballot paper.
This process takes place in rounds of votes, generally on Tuesdays and Thursdays. In each round, the MP with the fewest votes gets eliminated, along with any other MPs who’ve fallen below a minimum number of votes for that round.
Then, the approximately 100,000 Tory members hold a one-member-one-vote election, to pick between the top two options.
The winner then becomes the leader of the Conservative Party, and goes to Buckingham Palace to ask the Queen to appoint them as Prime Minister.
If Boris Johnson refuses to resign, could he be sacked?
Yes, he could be sacked, however, the process is not straightforward.
In order to trigger a no-confidence vote, 15% of Tory MPs must write to the chairman of the 1922 Committee. There are currently 360 MPs with the Tory whip, so, that means 54 must send letters.
However, there’s just been a no-confidence vote which the Prime Minister won, so, no further vote can be held until June 2023. This can be changed if the 1922 Committee’s 18-member executive change rules to hold another vote sooner.
Elections for a new executive are being held on Wednesday next week, so, this outcome is highly likely. So, a vote could be held this autumn or sooner, as long as enough anti-Boris Johnson MPs choose to do so.
Who could take over as the next Prime Minister?
The top “runners and riders” expected to take over from Boris Johnson as the next Prime Minister are:
- Rishi Sunak
- Sajid Javid
- Jeremy Hunt
- Liz Truss
- Nadhim Zahawi
- Ben Wallace
- Penny Mordaunt
- Tom Tugendhat
- Priti Patel
- Dominic Raab
Who is in charge after the Prime Minister resigns or is sacked?
Leaving as Tory leader would not automatically remove Boris Johnson’s job as Prime Minister.
To resign as PM he must go to Buckingham Palace and offer his resignation to the Queen. He has a role in naming his successor, based on who can command the confidence of Parliament. Importantly, he has some control over the timing of this.
Theresa May resigned as Tory leader in 2019 but remained as a “caretaker”— or “lame duck”—Prime Minister until her succession was chosen.