By Tara John, Aditi Sangal, Hafsa Khalil, Ivana Kottasová and Adrienne Vogt, CNN
From CNN's Sugam Pokharel in London
Buckingham Palace declined to comment on whether Queen Elizabeth II has had any communication with UK Prime Minister Boris Johnson on Thursday morning, Britain’s PA news agency reported.
The Queen is at Windsor Castle and the Court Circular recorded that she held her weekly audience by telephone with Johnson on Wednesday evening, according to the PA.
From CNN's Luke McGee at Downing Street
While Boris Johnson will announce his resignation, it is possible that he will remain in office until October, when the Conservative party meets for its annual conference.
Conventionally, when a Conservative leader resigns, they give the party time to hold a thorough leadership contest.
It is hard to predict how long this contest will take. When former Prime Minister David Cameron resigned in 2016, the process lasted just a few weeks as candidate after candidate pulled out, leaving Theresa May unopposed.
When Johnson himself ran in 2019, he went through several rounds of voting with his MPs, before being put to a final-two with the party membership. He defeated the former health secretary Jeremy Hunt in the final round. Hunt is expected to run for the leadership again.
While Johnson’s plan might be to stay on, given the near-collapse of his government, it is also possible that his MPs will demand an alternative interim leader.
Keir Starmer, the opposition Labour Party leader, responded to reports that UK Boris Johnson will resign as Conservative Party leader, calling it "good news."
"He was always unfit for office," Starmer said in a statement shared on Twitter. "He has been responsible for lies, scandal and fraud on an industrial scale. And all those who have been complicit should be utterly ashamed."
"They have been in power for 12 years. The damage they have done is profound. Twelve years of economic stagnation. Twelve years of declining public services. Twelve years of empty promises," the opposition leader said on Twitter.
"Enough is enough. We don't need to change the Tory at the top --- we need a proper change of government. We need a fresh start for Britain," he went on to say
From CNN's Ivana Kottasová and Tara Subramaniam
Boris Johnson's government has been plagued by a series of scandals, from accusations of his disregard for rules and revelations of illegal lockdown-breaking parties held in Downing Street, to allegations of impropriety and abuse by Conservative lawmakers.
Here's a look at some of the more notable scandals of his government, which have included furore over a flat refurbishment, prorogation of Parliament and parties held at Downing Street in defiance of coronavirus lockdowns.
Read the full story here:
From CNN's Luke McGee in London
A Downing Street spokesperson told CNN on Thursday that "the Prime Minister will make a statement to the country today.”
Earlier on Thursday, the British national broadcaster BBC reported that Boris Johnson is to resign as Conservative Party leader today.
PA Media earlier reported, citing a Downing Street source, that Johnson has spoken to Conservative Party 1922 Committee chairman Graham Brady and agreed to stand down, with a new leader set to be in place by the party conference in October.
Boris Johnson is to resign as Conservative Party leader, the BBC has reported.
From Manveena Suri in New Delhi and Lauren Kent in London
The newly-appointed Chancellor of the Exchequer Nadhim Zahawi urged Boris Johnson to resign on Thursday, saying in a letter posted on social media that at Downing Street on Wednesday night, he made it clear that he thought the Prime Minister should leave.
“Prime Minister, you know in your heart what the right thing to do is, and go now," Zahawi said in the letter on Thursday.
“Yesterday, I made clear to the Prime Minister alongside my colleagues in No10 that there was only one direction where this was going, and that he should leave with dignity. Out of respect, and in the hopes that he would listen to an old friend of 30 years, I kept this counsel private," Zahawi said.
“I am heartbroken that he hasn’t listened and that he is now undermining the incredible achievements of this government at this late hour.”
Zahawi was appointed on Tuesday evening, following the resignation of Rishi Sunak.
Michelle Donelan, who was only appointed as education secretary on Tuesday, has resigned from the post.
In her resignation letter to Boris Johnson, shared on Twitter Thursday, Donelan said she could "see no way that you can continue in post, but without a formal mechanism to remove you it seems that the only way that this is only possible is for those of us who remain in cabinet to force your hand."
After Sajid Javid resigned from the role of education secretary on Tuesday, Johnson gave Donelan the position in a cabinet reshuffle.
By CNN's Richard Greene in London
UK Prime Minister Boris Johnson is under increasing pressure from his own Conservative party to resign. Under the UK political system, between elections, only Conservative members of Parliament have the power to remove a sitting Conservative prime minister.
Here's how things could play out in the next hours or days:
If Boris Johnson refuses to quit, can he be pushed out by a vote of no confidence from Conservative party lawmakers?
As party rules stand right now, no. He survived a confidence vote on June 6, which should mean he cannot face another confidence vote for a year. But lawmakers who want to get rid of him have raised the possibility of changing the rules.
Even if they don’t go through the formal process of voting no confidence in Johnson, he may be doomed. Former UK Prime Minister Theresa May survived a confidence vote against her leadership in December 2018 -- by a bigger margin than Johnson got in June --and was still out of office by the following summer.
Does a Johnson resignation trigger a general election?
No. It starts the Conservative Party process for choosing a new leader of the party. UK Prime Ministers are not directly elected by the people; Johnson is prime minister because he is the head of the largest party in the House of Commons. The Conservatives will still be the largest party even if Johnson quits or is dumped, so the new head of the party will become prime minister.
How is the new Conservative Party leader chosen?
Leadership candidates need the support of at least eight lawmakers. If there are more than two candidates, Conservative party lawmakers hold round after round of votes to whittle the number of leadership candidates down to two. Then Conservative party members nationwide vote (by mail!) between the two finalists. The winner becomes leader of the party – and prime minister.
Who is prime minister while all this happens?
Boris Johnson. He’ll remain in office as caretaker prime minister until his replacement is chosen.
Then he submits his resignation to the Queen, in person. The Palace will announce officially that Queen Elizabeth II has accepted Johnson’s resignation, and will say who she has invited to become prime minister to replace him. (This is a formality; she will choose the leader of the Conservative Party.)
Does the new prime minister have to call a general election?
No. The United Kingdom isn’t scheduled to have another general election until December 2024. The new prime minister could choose to ask Parliament to vote for an early election, but isn’t required to do so.
