The senior civil servant in charge of the bullying inquiry into the home secretary, Priti Patel, is to leave her post next month in another major Whitehall shake-up. Helen MacNamara’s new role as a permanent secretary in an as-yet unidentified Whitehall department will heighten speculation that No 10 is clearing the way for Patel to be cleared of multiple bullying allegations. The director general of propriety and ethics has previously been identified as the person blocking No 10 from clearing Patel in a report that has been sitting on the prime minister’s desk for several weeks. MacNamara, who deputised for ousted cabinet secretary Mark Sedwill, will now take up a new position in another major Whitehall department. Her departure is the latest in a string of moves which have included Sedwill’s departure as national security adviser as well as cabinet secretary, the acrimonious exit of Philip Rutnam as Patel’s Home Office permanent secretary and the early retirement of Simon McDonald as permanent secretary at the Foreign Office. Boris Johnson’s top aide Dominic Cummings, an avowed Whitehall reformer, has said “a hard rain” is going to fall on the civil service. The job of ethics chief is crucial and sits at the heart of the No 10 operation. The appointed candidate oversees the provision of advice to all government departments on standards and ethics issues and manages public appointments. One Whitehall source said: “This move is a signal that No 10 will move on anyone who might challenge them on the legality or ethics of what Boris and Cummings want to do. “Control that office and you no longer have to stick to the rules when it comes to outside appointments.” MacNamara conducted an inquiry into the home secretary after former staff from three different government departments claimed that Patel had been guilty of mistreating staff. Her inquiry interviewed former staff from the Department for Work and Pensions, where Patel worked as an employment minister in 2015, and the Department for International Development where Patel was secretary of state in 2017. MacNamara also interviewed staff from the Home Office while investigating bullying claims from Rutnam, who resigned as permanent secretary earlier this year. Johnson authorised the inquiry four months ago, and insisted at the time that Patel would be exonerated. Leaks from Whitehall have since claimed that Patel was about to be cleared, but it has not yet been released. A report in the Financial Times on Wednesday claimed that the findings were being held back because its “robust criticisms” of Patel could be embarrassing. Rutnam is suing the home secretary after accusing her of lying and of bullying staff in an explosive statement released in February. MacNamara was promoted to the grade of a permanent secretary by Sedwill just before he stepped down from the Cabinet Office. She is said by former colleagues to be hugely ambitious, rigorous and unflappable, and capable of most jobs across the civil service. Sedwill’s promotion of MacNamara was said by some insiders to be a way of ensuring that she was protected from being “thrown under a bus” once he stood aside, according to one Whitehall insider. One of the few senior women in the new Downing Street machine, she had previously been cited by government sources as evidence that Johnson’s No 10 operation is not overwhelmingly male-dominated. A senior government source said MacNamara had been promoted to permanent secretary in a major delivery department which had not yet been confirmed. There are currently vacancies in the Foreign Office, the Ministry of Justice and the Department for Business, Energy and Industrial Strategy. The cabinet secretary post is also vacant – though the government source said MacNamara would not be taking this most senior role.