The latest on Boris Johnson's resignation

UK Prime Minister Boris Johnson's resignation announcement on Thursday has triggered the search for a new Conservative Party leader.

Under the UK political system, between elections, only Conservative members of Parliament have the power to remove a sitting Conservative Prime Minister.

Johnson indicated in his resignation speech that he plans to stay in office until a successor is chosen.

But it's not clear that the Conservative Party will stand for that in Johnson's case.

Take a look at who might replace Johnson as UK Prime Minister.

So, how will a new leader be selected and what can we expect?

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.

Is there any way to force Johnson to leave before a new Conservative Party leader is chosen?

Conservative lawmakers could, in theory, try to force him out themselves by calling a vote of confidence among Tory MPs. But Johnson survived a vote like that just a month ago.

Under current party rules, that means there can't be another party confidence vote in him for 12 months.

The rules could be changed, but it's not clear the Conservative Party wants to start that kind of infighting when Johnson has already said he's going, and when a leadership contest is under way.

Can't the opposition do anything to force Johnson out?

Labour leader Keir Starmer said Thursday that if the Conservatives didn't push Johnson out immediately, the opposition would call a confidence vote in the government among the entire House of Commons.

If the opposition won, it could theoretically lead to a general election — but even with all the chaos in the Conservative Party at the moment, they still have a big majority in the House of Commons, and they're not likely to want a general election at the same time as a leadership election. So the chances of the opposition bringing the government down now are slim.

As crisis after crisis has engulfed Boris Johnson in recent months, so rivals of Britain's beleaguered Prime Minister have been plotting behind closed doors to replace him.

After a dramatic cascade of nearly 60 resignations by lawmakers and government officials, Johnson was forced to begrudgingly announce on Thursday that he would step down.

Here are the potential contenders to succeed him as the new leader of the Conservative Party:

Rishi Sunak

The former chancellor was Johnson's presumed successor for several months after he won praise for overseeing Britain's initial financial response to the Covid-19 pandemic.

But Sunak's stock sank earlier this year after revelations that his wife had non-domicile tax status in the UK and that he held a US green card while a minister. He is, however, still among the bookmakers' odds-on favorites to take Johnson's job.

Sajid Javid

Like Sunak, Health Secretary Sajid Javid resigned this week over the botched handling of the resignation of Johnson's former deputy chief whip in a sexual misconduct scandal. Although Javid's resignation speech sounded very much like a pitch for Prime Minister, outlining how to reshape the party for future generations, it is not yet clear whether he will run.

Liz Truss

The foreign secretary, who has made her leadership ambitions known in recent years, could now be in pole position. Truss is popular among Conservative members, who would pick the eventual winner of a contest. Last month, a source working in the Foreign Office told CNN that Truss had been in "endless meetings with MPs," and that "it's been insinuated that she's seeing what her support base is, should the time come." Truss' office denied that any covert leadership bid was coming.

Penny Mordaunt

The trade minister is one of the bookmakers' favorites to replace Johnson. After last month's confidence vote, Penny Mordaunt declined to comment on whether she backed Johnson, raising eyebrows among Westminster observers when she said: "I didn't choose this Prime Minister."

Tom Tugendhat

A former British military officer who chairs the Foreign Affairs Select Committee, Tom Tugendhat has been one of Johnson's most robust critics and has made no secret of his desire to become Prime Minister.

Nadhim Zahawi

Less than two days after he was appointed to chancellor, replacing Sunak, Nadhim Zahawi publicly called on Johnson to resign. Until his promotion, Zahawi, who joined the cabinet less than a year ago, was considered an unlikely choice as the next Prime Minister. But his rise under Johnson has been rapid, making his mark with early success as vaccines minister amid the coronavirus pandemic and then as education secretary.

Jeremy Hunt

A former health and foreign secretary, Jeremy Hunt lost the 2019 leadership vote to Johnson. He has since styled himself as an antidote to Johnson and is without question the highest profile contender on the moderate, ex-Remain side of the party.

Read about the other contenders here.

The leader of the opposition Labour party has said Boris Johnson needs to go "completely" and "not cling on for a few months."

Earlier, Keir Starmer said that his party will bring forward a vote of confidence in Johnson if the Conservatives allow him to "cling on" to power.

Johnson is expected to remain as a caretaker prime minister until a new Conservative leader is picked.

"He needs to go completely — none of this nonsense about clinging on for a few months. He's inflicted lies, fraud and chaos in the country," Starmer said in a video posted to his Twitter account on Thursday.

Labour has not been in power since losing the 2010 election, and Starmer criticized 12 years of government under the Conservatives.

"And the change we need is not a change at the top of the Tory party, it's much more fundamental than that. We need a change of government and a fresh start for Britain," Starmer said.

The leader of the House of Commons, Mark Spencer, responded to concerns about a lack of ministers in government on Thursday, saying that "where there is a vacancy, those ministers will be appointed very soon, that the function of those departments will be up and running very quickly."

There are 122 government ministers in total, according to the Institute for Government, of which 28 have resigned. That means nearly a quarter of British government ministers have resigned this week, according to CNN's latest tally.

A further 31 government officials, including parliamentary private secretaries and trade envoys, have also resigned this week. 

Several of those officials have already been replaced. On Thursday morning, Johnson's government made several new appointments to his ministerial team and cabinet. However, many junior ministerial positions and parliamentary private secretary positions remain unfilled. 

"There are many talented people on the benches behind me that will be able to take up those roles," Spencer said in the House of Commons on Thursday afternoon. "They're probably all waiting by their phones." 

Labour (Co-op) MP Barry Sheerman said there is a "national crisis and a national emergency" and that there should be cross-bench cooperation in the coming weeks in the national interest. Labour MP Ruth Cadbury raised concerns that the basic functions of the government "currently seem to be collapsing." 

Irish Taoiseach Micheál Martin has extended his well wishes to outgoing British Prime Minister Boris Johnson and urged a "pulling back" by the UK from unilateral action on Brexit's Northern Ireland Protocol.  

In a statement, Martin commended Johnson's “leadership highlights,” including his response to the war in Ukraine as well as leading the United Kingdom through the pandemic. 

"From a personal perspective, I am conscious that he has been through a difficult few weeks and I extend my best wishes to him and his family for the future, following the announcement of his resignation," the taoiseach said. 

Martin also acknowledged the “strained and challenged” relationship between his government and Johnson’s over Brexit and highlighted the importance of a close partnership in maintaining “peace and prosperity on these islands.”

He called for Britain’s new leader to “return to the true spirit of partnership and mutual respect that is needed to underpin the gains of the Good Friday Agreement." 

Some background: The protocol is the part of the Brexit deal that sets out special trading arrangements for Northern Ireland in order to prevent a harder border between the country, which is part of the UK, and the Republic of Ireland, which is part of the EU. Johnson’s government however had laid out plans to make changes to the bill which were opposed by the EU.

Ireland “stands ready to work with a new UK PM on protecting our shared achievements in the peace process & our shared responsibility under international law on #Brexit,” Irish foreign minister Simon Coveney said on Twitter, adding his well wishes for Johnson and his family.

Lawmakers on both sides of the political divide in Northern Ireland have called on Johnson to immediately step down as prime minister, not wait until his successor as Conservative leader is in place.

A poll asking respondents to choose between UK Labour leader Keir Starmer and seven likely contenders to replace Boris Johnson as prime minister finds all the Conservatives trailing Starmer except ex-Chancellor Rishi Sunak, who led Starmer by one point. 

The poll found Starmer leading six other hopefuls: ex-Health Secretary Javid (by three points), Defense Secretary Ben Wallace (by 11 points), Foreign Secretary Liz Truss (by 12 points), Chancellor Nadhim Zahawi (by 13 points), former Health Secretary Jeremy Hunt (by 13 points) and former Defense Secretary Penny Mordaunt (by 15 points.) 

"For each of the following pairs, please indicate which you would most like to be prime minister," Respondents were asked in the poll.

Pollster James Johnson, who worked for Theresa May when she was prime minister, noted that these were the preliminary results and people may change their mind as the contest gets underway.

Sunak and Javid both resigned from high-profile positions in the Johnson Cabinet the day before the poll was launched. Their departures triggered an avalanche of more than 50 other resignations that ultimately forced Johnson to resign on Thursday. 

The poll, from JL Partners, surveyed 2,028 UK adults online on July 6-7, before Johnson announced his resignation. The margin of error on the sample is plus or minus 2.2 points.

UK's Prime Minister Boris Johnson held a cabinet meeting on Thursday, hours after he announced his resignation.

Deputy Prime Minister Dominic Raab and Culture Secretary Nadine Dorries were among the ministers seen entering Downing Street prior to the meeting.

Former British Prime Minister Sir John Major said it would be "unwise and may be unsustainable" for Boris Johnson to remain in the office of prime minister for a length of time while a new Conservative leader is chosen.

In a letter to the Chairman of the 1922 Committee of Conservative backbenchers, Sir Graham Brady, Major wrote, "The proposal for the Prime Minister to remain in office – for up to three months — having lost the support of his Cabinet, his Government and his parliamentary party is unwise, and may be unsustainable."

"Some will argue that his new Cabinet will restrain him. I merely note that his previous Cabinet did not — or could not — do so," he continued.

Major suggested that Johnson could resign as prime minister, and Deputy Prime Minister Dominic Raab could serve as acting prime minister until a new leader is elected. Another scenario he suggested was for Conservative MPs to elect a new leader to be installed as prime minister, and then party members could later endorse the new leader. 

"Neither of these options is ideal, but the interests of the country must be given priority over all else and, with so many long-term and critical issues before us, an imaginative response even at the risk of some bruised feelings within the party — is most definitely in the national interest," he concluded.

Dominic Cummings, who served as Boris Johnson's most senior advisor before becoming an outspoken critic of the Prime Minister, said he doesn't believe Johnson has given up on his fight to stay in the office.

Writing on Twitter before Johnson delivered his statement but after the news he intended to resign broke, Cummings said: "I know that guy & I'm telling you he doesn't think it's over." He added that he believes Johnson thinks he can "play for time" and "get out of this."

Cummings was one of Johnson's closest aides since he became Prime Minister in 2019, and he wielded unprecedented power and influence inside Downing Street.

He was often credited as the architect of two of Johnson's greatest political triumphs: Brexit and his landslide election victory in 2019.

Cummings left Downing Street amid a bitter fallout in November 2020 and has since become a vocal critic of the Prime Minister — most notably of his handling of the coronavirus pandemic.

Commenting after Johnson's address, Cummings said the speech was "in character" for the Prime Minister.

"Blames everyone else. Thinks he's the real victim. Sets up betrayal story for future Tory conferences & Telegraph columns," he said on Twitter.

"We're all in for a nightmare if he's allowed to squat," he added.