When do we find out the new Prime Minister? What time UK could announce new PM as Rishi Sunak leads race

Rishi Sunak could be declared as the UK’s next Prime Minister within hours after Boris Johnson ruled himself out of the race for No 10.

Sunak has become the firm frontrunner to be PM following Johnson’s decision to end his comeback bid, while uncertainty remains over rival Penny Mordaunt’s prospects of securing sufficient support from MPs.

Candidates need a minimum of 100 MPs to nominate them to make it onto the ballot paper for the parliamentary stage of the election process on Monday.

Here’s what you need to know about the leadership race and when the new PM could be announced.

What time could the new Prime Minister be announced?

Tory MPs will choose who they want as their new leader in the first stage of the contest on Monday, with candidates required to secure 100 nominations from MPs to proceed to the ballot.

Nominations close at 2pm with candidates who have reached the 100 nominations threshold announced before 2.30pm. A first ballot result will be announced at 6pm, with a second at 9pm if required.

Former Chancellor Sunak hit the threshold of 100 nominations from Tory MPs ahead of Monday’s 2pm deadline. He already had more than 140 public declarations of support on Sunday night, whereas rival Mordaunt, the Leader of the House, had fewer than 30.

Mordaunt’s campaign claimed on Monday that she has now received the support of 90 Tory MPs, and has urged others to back her so the party membership can select the next prime minister.

A campaign source said: “We have now passed 90. For the sake of the party, it’s important our members have their say.”

Her team are hoping that the departure of Johnson will see a swathe of MPs who were backing him or are yet to declare swing behind her instead. A campaign source confirmed she was still in the running on Sunday, arguing she was the candidate who Labour feared the most.

The source said: “Penny is the unifying candidate who is most likely to keep the wings of the Conservative Party together and polling shows that she is the most likely candidate to hold on to the seats the Conservative Party gained in 2019.”

Mordaunt appears to be far behind in the race but allies insist they are “confident” she will hit the target, which would see her face off against Sunak in an online ballot of Tory party members.

However, if she fails Sunak will be declared leader without contest and quickly succeed Liz Truss as Prime Minister – seven weeks after he lost out to her in the last leadership contest.

If Mordaunt does secure the required nominations, MPs will then decide which of the two candidates they prefer in an “indicative” vote. There will then be a final online poll of party members to decide the outcome, with the result due on Friday – unless one of the candidates pulls out.

A government source said the new Prime Minister could be in place as soon as Monday if the leadership race does not progress further.

Mordaunt could find herself under pressure to withdraw if she finishes a long way behind Mr Sunak in the poll of MPs, should it go to a vote, even though she is popular with the Tory grassroots.

There are some in the party who would like to see an uncontested “coronation” to avoid a repeat of what happened with Truss when members voted for a leader who did not have the backing of MPs.

Why did Boris Johnson drop out of the race?

Johnson dramatically withdrew from the leadership race on Sunday, having never officially entered, claiming he had the numbers but admitting he could not unite his warring party. In a statement on Sunday evening, he said there was a “very good chance” he could have been back in No 10 by the end of the week if he had stood.

Johnson said he would have been “well-placed” to lead the party to victory in a general election in 2024, but had come to the conclusion that “this would simply not be the right thing to do”.

He added that his efforts to “reach out” to rivals Sunak and Mordaunt to work together in the national interest had not been successful and so he was dropping out of the race.

In a statement, he said: “You can’t govern effectively unless you have a united party in Parliament. And though I have reached out to both Rishi and Penny – because I hoped that we could come together in the national interest – we have sadly not been able to work out a way of doing this. I believe I have much to offer but I am afraid that this is simply not the right time.”

Johnson lagged far behind Sunak in public declarations of support but claimed to have amassed at least 102 nominations. His withdrawal means the contest could be decided by early afternoon on Monday unless both the remaining candidates can get the support of 100 MPs.