There are two ways Labour could kick Sir Keir Starmer out of Downing Street.
A formal challenge
Under the Labour Party's rulebook, if there is no current vacancy for party leader, nominations may be sought by potential challengers.
Those seeking to replace Sir Keir must be nominated by 20 per cent of Labour MPs. The party currently has 403 MPs in the House of Commons, so each challenger will need the support of 81 MPs to force a leadership election.
Sir Keir will not be required to seek nominations should he be challenged and wish to fight on; as the sitting party leader, his name will automatically go on the ballot paper.
Those who have been Labour members for at least six months will be able to vote. Party members and affiliated supporters, such as trade union members, will then vote on a 'one person, one vote' basis. A candidate who receives more than half of the votes will be declared the winner.
If there are more than two candidates and none gets half of the votes, a redistribution of votes will take place according to preferences indicated on the ballot paper. The winner will then visit the King to confirm their position.
A Cabinet revolt
Perhaps a more likely way of forcing Sir Keir out would be to make it practically impossible for him to continue. A large section of the Cabinet quitting, or a huge groundswell in the parliamentary party, could be enough to convince him. That would clear the way for a wider contest, rather than requiring rivals to unite around a challenger.
Boris Johnson suffered a similar fate in 2022 when a slew of ministers quit.
There are two ways Sir Keir Starmer could be kicked out of Downing Street by his fellow Labour MPs
... and his MPs who want him gone
Debbie Abrahams (Oldham East and Saddleworth); David Baines (St Helens North); Paula Barker (Liverpool Wavertree); Apsana Begum (Poplar and Limehouse); Clive Betts (Sheffield South East); Olivia Blake (Sheffield Hallam); Jonathan Brash (Hartlepool); Richard Burgon (Leeds East); Ian Byrne (Liverpool West Derby); Irene Campbell (North Ayrshire and Arran); Beccy Cooper (Worthing West); Anna Dixon (Shipley); Neil Duncan-Jordan (Poole); Barry Gardiner (Brent West); Louise Haigh (Sheffield Heeley); Chris Hinchliff (North East Hertfordshire); Imran Hussain (Bradford East); Terry Jermy (South West Norfolk); Kim Johnson (Liverpool Riverside); Ruth Jones (Newport West and Islwyn); Peter Lamb (Crawley); Ian Lavery (Blyth and Ashington); Brian Leishman (Alloa and Grangemouth); Clive Lewis (Norwich South); Rachael Maskell (York Central); Andy McDonald (Middlesbrough and Thornaby East); John McDonnell (Hayes and Harlington); Anneliese Midgley (Knowsley); Abtisam Mohamed (Sheffield Central); Connor Naismith (Crewe and Nantwich); Simon Opher (Stroud); Sarah Owen (Luton North); Kate Osborne (Jarrow and Gateshead East); Euan Stainbank (Falkirk); Josh Simons (Makerfield); Graham Stringer (Blackley and Middleton South); Jon Trickett (Normanton and Hemsworth); Tony Vaughan (Folkestone and Hythe); Catherine West (Hornsey and Friern Barnet); Nadia Whittome (Nottingham East); Cat Eccles (Stourbridge).