THE Whitehall watchdog who led the Partygate inquiry that helped bring down Boris Johnson is to be Sir Keir Starmer’s new chief of staff.

Sue Gray, whose report exposed drunken excess in Downing Street during the Covid lockdown, is understood to have resigned from the civil service to take up the new post.

She had been second permanent secretary to the Cabinet Office.

Ms Gray took on the civil service investigation into allegations of coronavirus rule-breaking at No 10 in December 2021, going from an influential but little-known arbiter of conduct in Government to a household name seen as holding Mr Johnson’s fate in her hands.

Her move will be scrutinised by Parliament’s anti-corruption watchdog, the Advisory Committee on Business Appointments (Acoba), before formal confirmation.

It is understood that Rishi Sunak could in theory block the appointment.

The Prime Minister’s spokesman said: “Acoba will consider the information provided. 

“They’ll make necessary requests for information, they’ll consider it, they’ll come to review that should be applied to the appointment under the government’s business appointment rules, and they will provide a provisional recommendation and then the applicant is asked to confirm if they’re content to abide by the provisional advice.

“And then obviously the recommendations are then made to the relevant department or minister depending on who they are.”

Labour has not commented on whether Ms Gray has been appointed.

A spokesman said: “The process is ongoing, nobody has been offered the job.”