Jeremy Corbyn and Diane Abbott began their relationship in the late 1970s

Jeremy Corbyn faces questions over his failure to intervene in a damaging party dispute involving Diane Abbott after it emerged that the two are former lovers.

Details of their past relationship were revealed yesterday after Mr Corbyn was criticised for failing to step in when his shadow international development secretary verbally attacked a female MP who questioned his commitment to sexual equality.

Friends said that Mr Corbyn and Ms Abbott began their relationship in the late 1970s when the newly elected Labour leader was a councillor in Haringey, north London. He was separated from his first wife, Jane Chapman, a fellow Labour councillor, whom he had married in 1974.

A party colleague of Mr Corbyn and his then-wife said Ms Chapman had hoped they would