After the latest Labour antisemitism revelations, Tom Watson is the thorn Corbyn can’t pluck from his side

Inside Westminster: The deputy leader cannot be sacked because he too was elected by members. And now he’s on a one-man mission to save the party

“We have to sit tight; only the left can defeat Corbyn; eventually, they will do it to save Corbynism,” one critic of the Labour leader told me. But others take a different view, saying: “We can’t go on like this. At some point there will be an act of spontaneous combustion.” They predict a different outcome to 2016, when Owen Smith’s formal leadership challenge flopped.

That Labour MPs are having such anguished conversations tells us a lot about the dire state of their party. Jeremy Corbyn’s grip on it is loosening.

It was significant that his two closest shadow cabinet allies, John McDonnell and Diane Abbott, forced him into a change of policy on Brexit this week. Against the wishes of his inner circle, he conceded Labour would support a Final Say referendum on any Conservative Brexit deal, in order to stop a no-deal Brexit, and it would advocate Remain. But he tossed a bone to his ultra-loyal advisers by keeping his options open if there is a general election.