One of Jeremy Corbyn’s senior frontbenchers has resigned from the shadow cabinet after it was revealed she misled the public over what she knew about her son’s drug offences.

Kate Osamor, 50, the shadow international development secretary, had previously claimed she knew nothing about her son’s conviction until after he was sentenced last month.

But it emerged on Saturday that she was not only aware of the case against Ishmael Osamor, 29, but had written to the trial judge asking for leniency.

Ms Osamor continued to employ her son in her office following his conviction, which came after he was caught with drugs worth £2,500 at the Bestival music festival in Dorset last year.

When questioned by a reporter about her letter to the judge in her son’s case and when she first knew of his case Ms Osamor responded by saying she “should have come down here with a bat and smashed your face in”.

She then told the reporter to “f*** off” and threw a bucket of water at him, before calling police and accusing him of stalking her.

A few hours after the story broke it was announced that Ms Osamor was resigning from the shadow cabinet.