How is the Conservative party leader elected? Everything you need to know about Theresa May's potential no-confidence vote
Speculation over the prime minister's future in Downing Street has been rife
The senior backbencher and chairman of the European Research Group has clashed with Ms May over the Brexit withdrawal agreement, resulting in him calling for the prime minister to be removed.
As Ms May presented the deal to MPs in the House of Commons, Mr Rees-Mogg asked her to give him a reason why he should not write the letter.
Now that Mr Rees-Mogg has submitted his letter to the Conservative 1922 Committee, there are rumoured to be enough Tory backbenchers to trigger a vote of no-confidence.
Here is everything you need to know about how a vote would work:
What is the 1922 Committee?
All backbench Tory MPs, those without a position in the government, are represented by the 1922 Committee.
It has an 18-member executive that organises weekly meetings and other business.
How many letters are needed?
A challenge is triggered once 48 Conservative MPs (15 per cent of the parliamentary party) submit letters of no-confidence in Ms May to the committee.
If this number is reached Sir Graham Brady, who chairs the committee, would be responsible for arranging a confidence vote in Ms May.
How long will it take?
Under Conservative rules, the vote is held as soon as possible, on a date decided by the Sir Graham in consultation with Ms May.
The last no-confidence vote against a Conservative leader was under Iain Duncan Smith in 2003 when the party was in opposition.
The no-confidence vote was held the day after the chairman announced he had received enough letters.
What is the process?
Once a date is arranged, all Tory MPs can either vote for or against their leader. If May wins, she remains in office and cannot be challenged again for 12 months.
If she loses, she must resign and is barred from standing in the leadership election that follows.
Ms May's resignation would lead to an internal Conservative party leadership election, rather than a general election, but the process could still take months.
Candidates wishing to stand in the election have to secure the nomination of two parliamentary colleagues to gain a place on the party's leadership ballot.
The party - through a first past the post voting system - then holds a series of hustings, each time eliminating one contestant until just two names remain on the ballot.
When David Cameron resigned in 2016, the process to replace him was relatively quick and no vote of the party membership was required.
Ms May was the only candidate remaining after successive challengers withdrew from the race. She became prime minister the same week.
Will it impact Brexit?
A potential no-confidence vote and subsequent leadership race could have a serious impact on the Brexit negotiations and finalising the withdrawal agreement.
The deadline for the UK leaving the European Union is March, which provides a few months of breathing space.
Assuming there is a no-confidence vote and Ms May manages to win, it would bring into question whether she needs to go back and renegotiate with the EU, as it seems unlikely she can get this deal passed through parliament.
If May loses a no-confidence vote and is replaced, a new leader would have to decide how they approach the negotiations, potentially requesting an extension of Article 50.
Currently the EU27 are in agreement over the withdrawal agreement, potential changes to it and renegotiations could disrupt the balance.
The European Council is set to meet at the end of November to discuss the Brexit negotiations and they may have to reschedule to iron out these different scenarios.
As it stands, the situation regarding the negotiations is far from clear.
The Independent has launched its #FinalSay campaign to demand that voters are given a voice on the final Brexit deal.
Sign our petition here