A formal probe into allegations of bullying by Priti Patel was completed 'weeks ago' but Downing Street is delaying publication because of fears the findings will be politically embarrassing, officials have claimed.
The Cabinet Office investigation is said to contain 'robust criticisms' of the Home Secretary's behaviour.
The investigation was launched back in March after the Home Office's most senior civil servant, Sir Philip Rutnam, resigned.
Sir Philip claimed he had been the 'target of a vicious and orchestrated briefing campaign' and suggested Ms Patel was involved.
The Home Secretary had also faced allegations of bullying civil servants relating to her time at other Whitehall departments.
Ms Patel and her allies have always vehemently denied all of the allegations made against her.
A report into allegations of bullying by Priti Patel, pictured in the House of Commons on July 13, was launched by the Cabinet Office in March
Downing Street has faced repeated questions for months over when the investigation into whether Ms Patel breached the ministerial code will be published.
The Financial Times reported today that the probe, conducted by Helen MacNamara, the Government's director general of ethics and propriety, has been completed.
Officials told the newspaper that the investigation was finished 'weeks ago'.
One Whitehall official claimed the report had been sat on by Number 10 because of the 'tricky timing' of publishing it during the coronavirus crisis and because of concerns it could cause political embarrassment.
A Government insider told the FT the report contains 'robust criticisms' of Ms Patel's behaviour.
The Government is not expected to publish the report in full but is likely to release a summary.
Labour has called for the investigation's findings to be published without delay.
Nick Thomas-Symonds, shadow home secretary, said: 'It has been over four months since the Government promised a report into whether the Home Secretary broke the Ministerial Code.
The investigation was launched after the Home Office's most senior civil servant, Sir Philip Rutnam, resigned. Sir Philip claimed he had been the 'target of a vicious and orchestrated briefing campaign' and suggested Ms Patel was involved.
'There are now allegations of deeply inappropriate political interference in the publication of the report, both in terms of content and timing. The delay in producing it is totally unacceptable.
'Yet again the Government is acting in the interests of a Conservative Party elite, rather than the national interest.
'I’ve written to the Minister for the Cabinet Office calling for the report be published immediately, so that it can be properly considered before the recess.'