The post of leader of the opposition is a thankless task and Jeremy Corbyn deserves few thanks for the way he conducted it. Though the interminable Labour leadership contest still has more than a week to run, Mr Corbyn yesterday presided at his final prime minister’s questions in the House of Commons. The Labour leader has managed to be a significant figure in British politics because, by playing his part in events in such an unconvincing fashion, he has been a cause of the triumph for all that he held least dear.

That judgment may have to be qualified when it comes to Britain’s departure from the European Union, but only because it is not wholly clear what Mr Corbyn really did want. The official