Jeremy Corbyn “showed off” a naked Diane Abbott to impress his Left-wing friends when he was a young Labour activist, a new book has revealed.

The Labour leader invited fellow activists to his London flat where they were “shaken” to find Ms Abbott in his bed, one of his friends recalled.

The incident took place in 1979 soon after Mr Corbyn’s first marriage broke down because of his near-obsessive dedication to his political activism.

It is described in Comrade Corbyn, a biography of the Labour leader by Rosa Prince, which is being serialised by The Telegraph.