Think of the Parliamentary Labour Party as a regiment ordered over the top in the First World War. The soldiers know the generals haven’t a clue. They know the battle was lost before it began. The only question in their minds is who makes it back from the slaughter.

The projected casualty rates vary. Corbyn’s supporters want to justify the left continuing to cling onto the leadership by getting close to Ed Miliband’s share of the vote in 2015. If they succeed they will keep the Labour party at 30 per cent and give the Tories a majority of 60 or 70. London Labour MPs also feel that the losses can be contained. Outside of London, where pressure from the right is fiercest, Labour MPs phone each other and talk of meltdowns in safe seats in Yorkshire and the North East, of every marginal with a majority of less than 5,000 going, and of the Labour seat total going below Michael Foot’s tally of 209 seats in 1983, to 200, 180, 170, or lower.

What cannot be disputed is that the troops will mutiny against the men who have led them to the third (and worst ) defeat since 2010. But talk of 100 MPs responding by forming a breakaway centre party is premature. ‘The far left will have gifted the Tories an election,’ one senior Labour figure told me. ‘We’re not going to say “here, have the Labour party as a reward." If Corbyn does not have the decency to resign there will be another leadership challenge.'

Yvette Cooper and Chuka Umunna will both run either against Corbyn or a new left candidate if Corbyn steps aside. Everyone assumes he will only step aside if he is convinced that John McDonnell or someone else from the Campaign Group can receive the necessary nominations from MPs. If the numbers aren’t there, he will blame defeat on the Tory press, the insufficiently loyal liberal press, the 'Blairites’, the CPS failure to prosecute in the election expenses scandal, Nick Robinson or whoever else or whatever else come to mind, and carry on as if nothing has happened.

Umunna and Cooper will run, in part because they represent different traditions in the party and thus offer Labour members more choice, but mainly because the decision to run a single candidate against Corbyn last year is widely seen as a mistake. It made the leadership contest all about Corbyn, whether you were for or against him, and fed this supposedly modest man’s enormous vanity. All those desperate for an alternative to right-wing hegemony must hope three or more candidates would at least allow an honest debate about the appalling state of opposition politics in Britain and a break from Corbyn’s cult of the passive-aggressive personality.

You are not hearing from mainstream Labour politicians in this election, and not only because many of them are in a desperate fight to save their seats. The Morning-Star reading, Chavez-admiring, Stalin nostalgics must 'own' this election defeat, they believe. They will keep away and let them do their worst.

They are not going to announce a challenge as soon as the scale of the Tory victory is known in the early hours of 9 June. Owning the defeat does not mean firing up Corbyn and his supporters with news of another leadership election just after the polls close. It means allowing the scale of what he (and they) have done to sink in. The five more years of Tory rule stretching to 10 or more, if Labour does not change.

Elements in the Labour First network, which organises right-wingers in the constituencies and unions think any challenge can wait until the Labour conference in late September. They understand that the modern far left is not a patch on its ancestors, who got their way in Labour in the 1980s by packing meetings and making life so unpleasant for everyone else that their motions carried. Most Momentum activists are barely active at all, and the right is winning most battles to appoint conference delegates with ease. If they could win a slight majority on Labour’s National Executive Committee, maybe they could rewrite the rules to get rid of Ed Miliband’s electoral system, which cannot, what with one thing or another, be judged a resounding success.

Moderate MPs wholly reject this. They think that the public will find it ridiculous if Corbyn is allowed to stay on for months. More pertinently, the Brexit negotiations will begin in earnest once the German elections are over in September. Theresa May cannot be left free to mess them up without a serious opposition to scrutinise her.

My guess is that candidates will wait for the horror of the defeat to sink in over the weekend, and make their bids on the Monday. As they will want coverage on the lunchtime news, shall we say at 11am on 12 June?

Whether Cooper, Umunna or other candidates can beat the far left is anybody’s guess. A justifiably notorious poll of Corbyn supporters found that they put 'understanding what it takes to win an election' at tenth – yes, tenth – in their list of priorities. (Naturally, 'moving the party to the left' was number 1.) As Corbyn will have proved conclusively that he does not have what it takes to win an election, perhaps they won’t mind. There will certainly be an appeal for everyone who wants an effective opposition to join and form a mass movement of the centre in the Labour party that can outvote them.

I have no idea whether the appeal will work. But I do know this. If Corbyn holds on or is succeeded by another far leftist, there will be a new party because public pressure will demand it. Liberal England is not prepared to hang around and allow the Tories to run riot for years, maybe decades, while Labour struggles to regain what few senses it once possessed.