PRITI Patel has insisted she is “absolutely sorry” after an official probe found she had bullied staff.

In a broadcast interview, the Home Secretary said: “I’m sorry that my behaviour has upset people and I’ve never intentionally set out to upset anyone.

“I work with thousands of brilliant civil servants every single day and we work together day in day out to deliver on the agenda of this Government and I’m absolutely sorry for anyone that I have upset.”

Opposition politicians and former heads of the civil service were aghast that Ms Patel had not resigned after Sir Alex Allan, the Prime Minister’s independent adviser on ministerial standards, found that her conduct had broken the ministerial code.

However, Boris Johnson, who, as PM is the final arbiter on the code, adjudged that his Cabinet colleague had not broken it, made clear he had "full confidence" in her and that he “considers this matter now closed".

In response, Sir Alex, 69, a career civil servant, who has been the PM’s independent adviser on ministerial standards since 2011, resigned.

The public standards watchdog swiftly announced it would include the Patel case as part of its review of the ministerial code.

Lord Evans of Weardale, who chairs the Committee on Standards in Public Life, an official body that advises the PM on ethical standards in public life, said Sir Alex’s resignation was “deeply concerning” and the committee would be looking “urgently” at what had happened as part of the review.

Lord O’Donnell, the former Cabinet Secretary, insisted Ms Patel should have resigned.

“Every minister, it’s their responsibility to obey the ministerial code. The Prime Minister thinks there has been no breach of the ministerial code. I, personally, take the judgment of Alex Allan that actually there was a breach of the ministerial code.

“For something like bullying, in that case, it’s a bit like what would happen in the private sector, you just wouldn’t, and within the civil service, there are things like this, you would just say that’s just beyond the pale,” he added.

Lord Kerslake, another former head of the civil service, denounced Ms Patel’s refusal to resign as “reprehensible”. The crossbench peer added: “It is absolutely a clear-cut breach of the code on a very serious issue of bullying. In those circumstances in any other time, the minister would have gone.”

In March, a Cabinet Office investigation was launched over allegations that the Home Secretary had belittled colleagues and clashed with senior officials in three different departments. She was accused of shouting and swearing at staff.

It followed the resignation of Sir Philip Rutnam, the Home Office’s Permanent Secretary, who accused the Secretary of State of a “vicious and orchestrated briefing campaign” against him and is claiming constructive dismissal at an employment tribunal.

However, Ms Patel, 48, strenuously denied any wrongdoing. Allies described her as a “demanding” boss but not a bully.

Following his investigation, Sir Alex concluded the Secretary of State had not consistently met “the high standards required by the ministerial code of treating her civil servants with consideration and respect”.

He said her approach on occasions had amounted to behaviour “that can be described as bullying in terms of the impact felt by individuals,” adding: “To that extent her behaviour has been in breach of the Ministerial Code, even if unintentionally.”

But after Mr Johnson made clear he was over-ruling his adviser in favour of Ms Patel, Sir Alex quit, saying: “I recognise it is for the PM to make a judgement on whether actions by a minister amount to a breach of the ministerial code. But I feel it is right that I should now resign from my position as the PM’s independent adviser on the code.”

In her initial statement, Ms Patel stressed how she cared deeply about delivering on the Government’s commitments, noting: “I acknowledge that I am direct and have at times got frustrated.” She then thanked the PM for his support.

Earlier, Mr Johnson issued a Whatsapp order to Tory MPs, saying: “Time to form a square around the Prittster.”

Asked why he sent this message, Allegra Stratton, his Press Secretary, said: “It was to recognise that today she is coming forward with a full and frank apology…He wanted her parliamentary colleagues to support her in acknowledging this is a testing day for her.”

She insisted Mr Johnson “loathes bullying” and took the allegations against his Cabinet colleague “seriously” but did not consider her to be a bully.

Ms Stratton spoke of “mitigating factors” such as there was no evidence of the impact on others of the Home Secretary’s behaviour at the time as there was no immediate feedback plus the top civil servant at the Home Office had stressed how relations between ministers and officials had since “improved considerably”.

Ministers are usually expected to resign if they breach the code. Mr Johnson’s decision to stand by Ms Patel sparked fury from opposition MPs.

Sir Keir Starmer said: “It is hard to imagine another workplace in the UK where this behaviour would be condoned by those at the top.”

His Labour colleague Jess Phillips said it was an “utter disgrace” and that any Conservative MP “seeking to defend this is utterly without reason or comprehension”.

Joanna Cherry for the SNP said: “This entire episode is yet another example of the total lack of accountability at the heart of this Tory Government and the self-serving politics dominating Downing Street.”

Downing Street made clear the full report into Ms Patel’s conduct would not be published so that those who gave evidence would be protected.