BORIS Johnson did not "misdirect" himself over the Ministerial Code when deciding if Witham MP Priti Patel's behaviour towards civil servants breached its standards, High Court judges have ruled.

The FDA union, which represents senior public servants, brought a judicial review over the Prime Minister's decision last year to back the Home Secretary following allegations of bullying.

Lawyers for the union sought a declaration that Mr Johnson had "misinterpreted" the term "bullying" as covered by the code, arguing he made a "misdirection of law" when reaching his decision.

But in a ruling today, Lord Justice Lewis, sitting with Mrs Justice Steyn, dismissed the FDA's claim.

The judge said: "Reading the statement (made by Mr Johnson) as a whole, and in context, we do not consider that the Prime Minister misdirected himself in that way."

He said judges had not been provided with the details of the allegations made against Priti Patel, but said the court had not been asked to express a view on whether she did the things alleged nor what sanctions, if any, would be appropriate.

In an investigation into Ms Patel's behaviour, published in November last year, the Prime Minister's then adviser on ministerial standards, Sir Alex Allan, found she had not always treated civil servants with "consideration and respect".

Sir Alex concluded: "Her approach on occasions has amounted to behaviour that can be described as bullying in terms of the impact felt by individuals. To that extent her behaviour has been in breach of the Ministerial Code, even if unintentionally."

Ms Patel previously issued an "unreserved, fulsome apology" and said there were "no excuses" for what happened.

Mr Johnson said the Home Secretary was "unaware" of the impact she had and he was "reassured" that she was "sorry for inadvertently upsetting those with whom she was working".

After "weighing up all the factors", he concluded the code had not been breached.

FDA general secretary Dave Penman said in a statement after the ruling that despite the overall dismissal of the union's claim, the judgment was an "important step forward in the battle to ensure that ministers are held to account for their behaviour in the workplace".