One of Jeremy Corbyn’s most powerful aides committed gender-based harassment of a female colleague, a judge has ruled.

Andrew Murray, a former communist who advises the Labour leader on policy, mistreated a female colleague in his former role as chief of staff to Len McCluskey, leader of Unite, in 2015.

Murray, 61, had been asked to deal with “a sickening and orchestrated campaign of bullying and sexual harassment” against the woman, a regional official at the union’s Heathrow branch.

However, an employment tribunal found that he had handled her case in a way that “violated her dignity” and itself represented unlawful harassment under the Equality Act.

The victim, Sally Nailard, 54, said she was “verbally attacked, abused and threatened” and “made to feel physically unsafe”