Boris Johnson’s adviser on the ministerial code has resigned after the PM backed Home Secretary Priti Patel over a bullying inquiry.

The government’s standards adviser Sir Alex Allan found that Ms Patel’s behaviour had breached the code.

But Mr Johnson rejected Sir Alex’s findings and said he had “full confidence” in Ms Patel.

Ms Patel released a statement saying she was sorry “that my behaviour in the past has upset people”.

Ministers are normally expected to resign if they break the code and there are no known cases of a minister staying in post following a breach.