Labour’s general secretary sent an email to Jeremy Corbyn’s personal account promising to intervene in one of the party’s most notorious antisemitism cases — before telling him she had “deleted all trace of the email”.

A new BBC Panorama documentary, which will be broadcast tonight, alleges that Mr Corbyn’s top team tried to influence the party’s national constitution committee (NCC) before it ruled on the case of Jackie Walker, an activist whose membership had been suspended after suggesting that Jews controlled the slave trade.

In May last year Jennie Formby, Labour’s general secretary, wrote in an email: “The NCC cannot be allowed to continue in the way that they are at the moment, and I will also be challenging the panel for the Jackie