The phrase ‘existential crisis’ is thrown around too easily. But it is hard to find a better description of the state of the Labour party, whose members and supporters overwhelmingly oppose Brexit but whose leader and advisors cling to the old Communist party line that the EU is a ‘capitalist club’. Previously solid followers of Jeremy Corbyn — Clive Lewis in Norwich, Lloyd Russell-Moyle in Brighton and many leftish London MPs — know that Brexit may cost them their seats. And nothing makes a politician move faster than the prospect of unemployment.

Even Labour can’t stagger on like this indefinitely. Tom Watson will mount a hostile leadership challenge to Jeremy Corbyn if none of the party’s other pro-Europeans is willing to extricate Labour from the wreckage of Brexit. As millions of supporters peel off to the Liberal Democrats, nationalists and Greens, and as Boris Johnson and Nigel Farage threaten to shift Britain decisively to the right, Watson is at the end of his tether — and it is easy to see why.

Labour’s crisis is as much moral as political. To the young, who projected their fantasies of what a socialist leader should be on to Corbyn’s bland features, his Brexit policy is an almost personal betrayal. A year ago, they could fool themselves that ‘Jeremy’ was playing a tactical game: that underneath his ‘constructive ambiguity’ (and what a weasel euphemism for dishonesty that was) his heart was in the right place. No one can believe that now. If liberals and leftists want to oppose Brexit, they have to oppose Corbyn.

No one I’ve spoken to in Labour believes recent reports that he is suffering from a mysterious malady that has left him ‘too frail’ to become PM. He looks like yesterday’s man because he is a narcissist, who loved the applause of the Glastonbury crowds and knows now that his support for Brexit and inability to break from the anti-Semites who have surrounded him throughout his career have cost him their adulation.

Corbyn is also suffering because, despite the educational privileges he received, he remains a man of limited intelligence who has lost the comfort blanket that once kept him safe. For decades, Corbyn blocked out his intellectual shortcomings by cocooning himself in the certainty of far-left dogma. That protection is crumbling, as the tight band of post-Marxists that has guarded him since 2015 divides into rival factions of fanatical purists and grudging realists. John McDonnell, in particular, is making no secret of his despair at the damage Corbyn is doing to his party’s chances of power — and his own chances of becoming chancellor.

The animosity is reciprocated. Corbyn, McDonnell, Seumas Milne and others from the leadership clique used to discuss tactics the night before shadow cabinet meetings. Corbyn has now excluded McDonnell from his ever-decreasing circle of confidants.

On the face of it, McDonnell is in the best position to move the party on. Momentum’s Jon Lansman, a secular Jew who, somewhat late in the day, has noticed the racism on the left, is now his man. McDonnell has also been wooing the Tribune group of about 75 ‘soft left’ Labour MPs via the offices of Lyn Brown from his shadow Treasury team, and a leading Tribunite.

An alliance between the soft and hard left opens the prospect of Corbynism surviving Corbyn. There are rumours of a deal circulating among Labour MPs. McDonnell would offer his and Momentum’s support to Emily Thornberry, Keir Starmer or Angela Rayner, depending on who would be most likely to win. They would promise to keep him as shadow chancellor and promote his protégés Rebecca Long-Bailey and Richard Burgon.

A prospective Labour leader would be mad to strike a bargain, as it would hand McDonnell effective control of the party. But the soft left is called ‘soft’ for a reason, and it may well be naive enough to fall for McDonnell’s offer. There is a deeper problem. The strategy might have worked six months ago. But the pace of the Brexit emergency renders calculations that once made sense redundant.

Unless Corbyn retires in the next few weeks, the only way to replace him before the country enters its worst crisis since 1945 is by challenging him. The left can’t do it, much though many of its more thoughtful members may want to. The personality cult they built around Corbyn has trapped them. I do not mean to offend religious readers with delicate sensibilities when I say the left turned a dim, elderly backbencher into the socialist equivalent of Christ. They made him a messiah sent to save us from neo-liberalism, and cried in pain as he suffered for our sins at the hands of the mainstream media, the establishment and, well, the Jews. Corbyn plays the victim card as if it is the only card he has left. ‘The rich and powerful are so worried about a Labour government redistributing wealth and power that they’re stepping up their attacks on me, those close to me, my staff and our movement,’ he tweeted last week, deftly extending the aura of martyrdom over his chief staffer, Seumas Milne.

His former allies will have some explaining to do if they tell the faithful he was just another false prophet all along. Khrushchev waited until Stalin was dead before he denounced his personality cult. The same constraint leaves McDonnell tongue-tied.

A continuity Corbyn candidate cannot run as long as Corbyn continues to run the show. Only an avowed political opponent can challenge him. Several potential Labour leaders who could speak for centre-left Britain have been bullied into silence. Watson, on the other hand, hasn’t been cowed. He has fought anti-Semites on the left and defended the British interest in remaining part of Europe and the Labour interest in being an internationalist rather than an isolationist party.

Few thought that Watson wanted to be leader. Since being elected deputy leader, he has seen his job as keeping Labour together until the infantile leftist moment passed. He hoped to encourage a new generation of leaders through his Future Britain group of Labour politicians. But time is running out and, at this rate, there might not be a future. If no one else is willing to intervene, my understanding is that he will do just that.

Unless Corbyn retires in the next few weeks, the only way to replace him is by challenging him

blogs.spectator.co.uk Nick Cohen writes regularly for Coffee House.