The Conservatives are to start a three-month leadership contest this week, due to end with the announcement of a new Tory leader on 2 November.
Nominations will open on Wednesday, with candidates needing a proposer, a seconder and eight nominations to pass the first round.
MPs will choose the final four candidates, who will then have a chance to speak to party members at the Conservative conference.
MPs will then whittle those down to the final two candidates, with the final winner chosen by Conservative Party members.
The announcement comes as Rishi Sunak ally Mel Stride, the shadow work and pension secretary, said he was “considering” announcing his candidacy for the race.
On Monday, Mr Sunak formally stepped down as leader of the Conservatives starting the process to elect his replacement.
He will remain acting leader of the party until a successor is appointed.
The plans allow as many as 11 of the 121 surviving Tory MPs one week to file their nominations – nominations close on Monday afternoon.
The ballot of party members will close on 31st October.
Only members who have been a member for 90 days or more prior to the ballot closing, and have been an active member at the time of the nominations for candidates opening, will be eligible to vote, the party said.
No-one has yet officially confirmed they will stand.
But other potential leadership candidates include former immigration minister Robert Jenrick, former home secretaries Suella Braverman and Dame Priti Patel, shadow home secretary James Cleverly, shadow security minister Tom Tugendhat and shadow communities secretary Kemi Badenoch.
The BBC understands Mr Sunak had wanted to stand down earlier, in order to allow the party to move on.
He is now likely to remain in post for Labour’s first Budget since the party won a landslide election at the start of July.
Mr Sunak said it was in “the national interest” for him to stay in post to allow “a smooth and orderly transition to a new leader of the opposition”.
He said: “This will allow our party to fulfil its role as the official opposition professionally and effectively.
“I believe this is what is best for the Conservative Party and, most importantly, our country.
“I am confident that this timetable decided by the Party Board and the 1922 Committee will allow for a thoughtful, professional and respectful contest.”
