Boris Johnson has been asked to release a government report on the fabricated claim against Home Secretary Preity Patel.

Lord Evans, the former head of MI5 and current adviser to the prime minister on public life standards, believes the results of the prime minister’s investigation should be disclosed to the home secretary.

The Cabinet Office investigated Ms Patel’s claim that she had worked for civilian employees in the Home Office as well as in previous departments.

However, the results of the investigation have not yet been made public.

Sir Philip Rutnam, MS Patel’s top civil servant, resigned earlier this year, claiming that there had been “rogue and orchestrated” propaganda against him and that the Home Secretary had been silenced.

After regular reports of a huge crack in one of them, the 33-year-old civil service veteran fired all the guns and launched an angry attack on MS Patel.

He lied against her and said he received allegations that he shouted and swore to the staff.

The former official said he had been the victim of a ‘briefing campaign’ and had refused a ‘financial settlement’ from the cabinet office in his decision to resign publicly.

The official was accused of briefing the Home Secretary in the media, but he denied the allegations.

The staff also accused the Home Secretary of bullying and belting officials at a meeting at the Home Office.

They complained that he had made unreasonable claims and created an ‘atmosphere of fear’.

More than eight months after MS Patel’s investigation began, the report has yet to be released.

In an interview with The Times, Lord Evans now said the delay could give the impression that the allegations were “blown away”.

He further added that he was concerned about the failure to conduct an independent investigation into Housing Secretary Robert Genrick.

Genrick came under fire in June after he accused the planning inspector of overlulling for a development approval led by Sir Richard Desmond.

Lord Evans said: ‘When you get these allegations that don’t really fall into bed they are just told that they have been pressured and I don’t think it’s ideal for public confidence and public standards.

‘The Preeti Patel case could be an example. The cabinet office has somehow investigated. It was not published so it is very difficult to know if there was anything here.

The same is true of the allegations against Robert Genrick. It was decided that they did not need further investigation. I don’t know because I’m not saying what happened, or I don’t know anyone else, because there was no investigation. ”

Sir Philip’s resignation came after a weeks-long standoff over the management of the home minister’s father, Patel, and a damaging dispute between officials and the home secretary.

It was claimed that MS Patel had promised to get Sir Philip Release from the hands of a senior official on the eve of Christmas, but the top Mandarin refused.

Sir Philip said in his statement that his experience was ‘extreme’ and part of a ‘broader pattern’ of government.

He told reporters: ‘In the last ten days I have been the target of a vicious and orchestrated briefing campaign.

‘It has been alleged that I have briefed the media against the Home Secretary.

‘This is a complete lie with many other claims.

The Home Secretary has categorically denied any involvement in the campaign in the cabinet office.

‘I’m sorry, I don’t trust him. He did not do what I would expect him to do to dissuade me from commenting, ‘he added.