THE influential backbench 1922 committee has announced the rules for the leadership contest to replace Boris Johnson as Prime Minister.

Sir Graham Brady, the committee chair, also revealed that the winner of the contest will be announced on September 5, with the shortlist set to be decided this week before Westminster goes into summer recess. 

The committee elected its new executive to preside over the vote for the incoming Tory leader on Monday night, shortly followed by a raft of new rules to reduce the crowded field of 11 Tory MPs running for the party's leadership. 

In a bid to quickly slash the number of candidates, the threshold for nominations to get through to the first stage was raised from eight to 20. 

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Nominations will open and close on Tuesday 12 July, followed by a vote by MPs on Wednesday and a second on Thursday to whittle down the contenders to the final two - before the vote opens up to the membership and hustings begin. 

Hopefuls will need to get at least 30 votes to make it into the second round. 

According to Sky News, former chancellor Rishi Sunak has the most endorsements so far (38), followed by Penny Mordaunt (22), Tom Tugendhat (19) and Liz Truss (15). 

Those at risk of being kicked out of the race in the first stages are Foreign Office minister Rehman Chishti (0 endorsements), Grant Shapps (8) and Sajid Javid (10). 

Speaking outside the House of Commons on Monday night, Brady told broadcasters: "The executive met this afternoon and since that [meeting] with the Conservative party we have agreed the way forward for the leadership election.

"Nominations will open and close tomorrow. We will have a first ballot on Wednesday and a second ballot likely on Thursday.

"We expect 20 supporters for each candidate, a proposer and seconder who will be public and 18 others.

"We will also expect that on the first ballot any candidate to proceed must have won at least 30 votes from parliamentary colleagues."

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Asked if the rules could discriminate against "lesser-known candidates", such as Chishti who has no endorsements, Brady said: "What we tried to do is find a balance where we're making sure the parliamentary stages are concluded reasonably rapidly before the summer recess.

"But we do believe we can have that discussion within the party. Obviously, we know parliamentary candidates are running within these elections and we need to make sure there is a decent amount of time before the result is announced on the fifth of September.

"We need to make sure there's a reasonable amount of time for the party membership in the country to have a chance to meet, question the candidates at regional hustings."

Brady added that the party will get down to the final two as "quickly as that happens", and they will hold "successive ballots" until there are only two candidates left.