LONDON (AFP, REUTERS) - Mr Boris Johnson resigned as Britain's prime minister on Thursday (July 7), triggering a search for a new leader.

Speaking outside No. 10 Downing Street, Mr Johnson said he would remain in office until a new prime minister is elected, but some Conservative members of parliament want him to be replaced immediately.

Party grandees hope to conclude the two-stage contest well before the Conservative party holds its annual conference in October.

Here's how the process to find Mr Johnson's successor will work.

Candidates put forward

Candidates putting themselves forward for the leadership, and there could be many, must be nominated by other Conservative lawmakers.

How many nominations they require will be set out by the committee in charge of running the contest. In 2019, it was eight nominations for each candidate.

Conservative MPs vote

The 358 Conservative Members of Parliament whittle down the nominees to two, via successive rounds of secret ballot in which the bottom candidate is eliminated each time.

Votes previously have been held every Tuesday and Thursday, but Parliament is due to break for its six-week summer recess on July 21 so the process may have to be accelerated.

Postal vote

Tens of thousands of grassroots party members vote in a secret postal ballot, with the winner named the new leader and the prime minister.

He or she does not have to call a snap election, but has the power to do so.

How long will it all take?

The duration of the leadership contest can vary, depending on how many people put themselves forward.

In 2016, Mrs Theresa May became leader less than three weeks after Mr David Cameron resigned and all other contenders dropped out mid-race.

In 2019, Mr Johnson faced former health minister Jeremy Hunt in the run-off ballot of Conservative members to replace Mrs May, and took office two months after she announced her intention to resign.