A long-awaited investigation into allegations of bullying by Priti Patel must be published without delay, Labour has demanded amid reports it found she broke the rules for ministers.

A draft report last summer found the Home Secretary had breached the requirements in the ministerial code to treat civil servants with consideration and respect, according to the BBC.

Channel 4 News said the full report would not be published although its findings would be covered in the annual report of the Prime Minister’s adviser on ministerial interests, Sir Alex Allan.

He was said to have concluded that while some of her behaviour broke the rules, even if “unintentionally”, her conduct since had been “more positive”.

He was also said to have criticised some Home Office officials for a lack of flexibility in taking her directions and a failure to give her better feedback.

Earlier, the Financial Times reported that Boris Johnson had decided only to issue her with a written warning rather than dismissing her from the Cabinet as would normally be the case for a breach of the code.

Shadow home secretary Nick Thomas-Symonds said the Prime Minister appeared to be engaged in a cover-up and called for the immediate publication of the inquiry’s findings.

“These revelations could not be more serious,” he said.

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

“His actions are all but condoning bullying in the workplace. In any other area of life this would not be acceptable. Yet again, it seems to be one rule for them and another for everyone else.

“The report needs to be published in full immediately and both the Prime Minister and Home Secretary must come before Parliament to answer questions on this mess.”

Patel
Sir Philip Rutnam accused Ms Patel of a ‘vicious’ briefing campaign against him (Helen William/PA)

Dave Penman, general secretary of senior civil servants’ union the FDA, said: “In his foreword to the ministerial code, Boris Johnson said: ‘There must be no bullying and no harassment’.

“If, as is being suggested, substance has been found in some of the allegations against the Home Secretary, then the Prime Minister should have no choice but to conclude that the code has been breached.

“As Prime Minister, he is the sole arbiter of the ministerial code but he is also Minister for the Civil Service.

“Having pledged his support for the Home Secretary when the investigation began, and now sat on the report since the summer, he has already undermined confidence in this being a fair and impartial process.”

The calls came as the BBC reported that Mr Johnson could announce his conclusions as early as Friday.

A Cabinet Office investigation was launched in March over allegations that Ms Patel belittled colleagues and clashed with senior officials in three different departments.

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

Ms Patel has expressed concern at the “false” claims, and allies have described her as a “demanding” boss but not a bully.

Earlier this week, the former cabinet secretary Lord Sedwill told MPs the investigation was now “with” the Prime Minister, who had discussed it with his independent adviser on ministers’ interests, Sir Alex Allan.

A Government spokesman said: “The process is ongoing and the Prime Minister will make any decision on the matter public once the process has concluded.”