The Conservatives are set to launch a three-month leadership contest this week, ending with the announcement of a new Tory leader on November 2.
Nominations open Wednesday, with candidates needing a nominator, second and eight nominators to pass the first round.
MPs will choose the final four candidates, who will then have the opportunity to speak to party members at the Conservative conference.
MPs will then narrow down the final two candidates, with the final winner chosen by Conservative Party members.
The announcement comes as Mel Streide, the shadow work and pensions secretary Rishi Sunak’s partner, said he was “considering” announcing his candidacy for the race.
On Monday, Mr Sunak formally stepped down as leader of the Conservatives, beginning the process of choosing his replacement.
He will remain the party’s acting president until a successor is appointed.
The plans allow 11 of the remaining 121 Tory MPs a week to file their nominations – with nominations closing on Monday afternoon.
Voting for party members ends on October 31.
The party said that only members who have been members for 90 days or more before the close of polls and who were active members when nominations for candidates began are eligible to vote.
No one has officially confirmed their standing yet.
But other potential leadership candidates include former immigration minister Robert Jenrick, former home secretaries Suella Braverman and Dame Priti Patel, shadow home secretary James Wise, shadow defense minister Tom Dugentat and shadow communities secretary Kemi Patenock.
The BBC understands Mr Sunak wanted to stand down earlier to allow the party to move.
He is now likely to remain in office in Labour’s first budget after the party won a general election in early July.
Mr Sunak said it was in the “national interest” for him to remain in office to allow a “smooth and orderly transition to the new leader of the opposition”.
He said: “This will allow our party to fulfill its role as the official opposition professionally and efficiently.
“I believe this is what is best for the Conservative Party and, more importantly, for our country.
“I am confident that this schedule, determined by the Party Board and the 1922 Committee, will allow for a thoughtful, professional and respectful competition.”
