Does Jeremy Corbyn know what is being done in his name and endorse it? Or is the Labour leader so naive, stupid or ignorant that he cannot see the nastiness engulfing his party? Or does he merely turn a blind eye to the bullying and abuse carried out on his behalf? It can only be one of these three, any of which would be bad for the leader of a party that exists to promote tolerance and equality. Leadership is a test of character and Mr Corbyn’s deepest flaws have been exposed by this X-ray of his soul.

The row over antisemitism illustrates a wider problem. Moderate Labour MPs Dame Margaret Hodge and Ian Austin face disciplinary action for criticising the party’s policy while extremists