Who will succeed Jeremy Corbyn and how does a Labour leadership contest work?

The battle to succeed Jeremy Corbyn as Labour leader is already in full swing after the party suffered its worst defeat at the ballot box since 1935.

Mr Corbyn said he would stay in place until another leader has been appointed but contenders for the Labour crown are already jockeying for position behind the scenes.

As the contest gets under way, The Independent takes a look at how the Labour Party elects its leader.

When will the leadership contest take place?

The timetable for the leadership race will be decided by Labour’s ruling body, the national executive committee (NEC), which is made up of MPs, trade union officials and members.

Contests can take months but John McDonnell said it was likely to take between eighr and 10 weeks, which means there could be a new Labour leader in place by March.

The NEC will certainly want a new leader in place ahead of the local election in May 2020.

Corbyn has said he will remain in place until a replacement is found, as there is no deputy leader to fill his shoes after Tom Watson stood down as an MP.

The party rulebook says when both the deputy leader and the leader are “permanently unavailable”, the NEC will conduct a postal ballot of members and could appoint a temporary leader from the shadow cabinet.

Who can stand?

Only Labour MPs can stand to be leader. Under the rules, candidates must secure backing from 10 per cent of the parliamentary Labour party and the European parliamentary Labour party.

However, the EPLP will cease to exist if the UK leaves the EU on 31 January, so it is unlikely that contenders can count on the backing of MEPs to get on the ballot paper.

Any would-be leaders also need support from 5 per cent of constituency parties or 5 per cent of affiliated groups, two of which must be trade unions.

The rules were changed in 2018 to reduce the influence of the PLP on who could get on the ballot paper, cutting the threshold from 15 to 10 per cent.

Who can vote?

Labour party activists, MPs, members of affiliated trade unions and socialist societies all have a single vote each.

In 2015, the rules were changed to allow registered supporters to cast a ballot in a leadership contest. The flood of voters who signed up for a £3 fee overwhelmingly backed Corbyn.

The fee was raised to £25 in 2016, ahead of the leadership challenge against Corbyn by Owen Smith.

Voters rank the candidates in order of preference, which means anyone who wins more than half the vote is automatically elected.

If no one meets that threshold, the candidate with the lowest votes is eliminated and their second preference votes are distributed to other candidates. This process continues until one candidate receives more than 50 per cent of the votes.

Who might stand to be leader?

Shadow cabinet members such as Sir Keir Starmer, Emily Thornberry, Dawn Butler and Angela Rayner are said to be considering their chances, while Corbynites are rowing in behind Rebecca Long-Bailey, the shadow business secretary.

Lisa Nandy, Jess Phillips and David Lammy are also understood to be mulling a tilt from the back benches.

No one has officially declared their candidacy yet, but Nandy said she was “seriously thinking about it” on Sunday.

What about the deputy leader?

The position is vacant since Watson decided to quit, so the NEC may decide to run the election alongside the leadership contest.

Some of the people named as runners and riders for the leadership may decide to stand for the deputy job instead. There is some speculation about joint tickets, with Richard Burgon, the shadow justice secretary, saying he would back Long-Bailey but would consider running for the deputy role.