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

The prime minister judged that Ms Patel had not breached the ministerial code despite the inquiry report’s author saying she had “not consistently met the high standards expected of her”.

In the report into Prit Patel’s conduct it said

It was clear from Sir Alex’s advice that at times there have been difficult working relationships all round. Sir Alex’s advice found that the Home Secretary had become – justifiably in many instances – frustrated by the Home Office leadership’s lack of responsiveness and the lack of support she felt in DfID three years ago. He also found, however, that the Home Secretary had not always treated her civil servants with the consideration and respect that would be expected, and her approach on occasion has amounted to behaviour that can be described as bullying in terms of the impact felt by individuals.

He went on to advise, therefore, that the Home Secretary had not consistently met the high standards expected of her under the Ministerial Code.

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

In a statement, the government said the Prime Minister has full confidence in the Home Secretary and considers this matter now closed. He is grateful to the thousands of civil servants working extremely hard to support the delivery of the Government’s priorities.

On resigning Sir Alex Allan said

“I recognise that it is for the Prime Minister to make a judgement on whether actions by a Minister amount to a breach of the Ministerial Code. But I feel that it is right that I should now resign from my position as the Prime Minister’s independent adviser on the Code.”

Nick Thomas-Symonds MP, Labour’s Shadow Home Secretary, responding to reports that Priti Patel was found to have broken rules on ministers’ behaviour by a Cabinet Office inquiry, said:

“These revelations could not be more serious.

“This has all the hallmarks of a cover up from the Prime Minister and raises fundamental questions about his judgement.