Dave Penman, head of the FDA union for senior civil servants, told the BBC the “tone and culture” in Number 10 had led to “exasperation” in Whitehall and was “in some ways worse than the Dominic Cummings/Boris Johnson era”.

That’s because people in Whitehall were surprised and disappointed that someone who had led a public body – Sir Keir had been in charge of the Crown Prosecution Service before entering politics – had not acted in a way significantly differently than the previous adminstration.

The anonymous briefings against Sir Chris when in post – and when his resignation was being negotiated – has alienated other civil servants, says the FDA, who are concerned that they will get blame rather than previously promised support from ministers.

Former Cabinet Secretary Lord O’Donnell denounced the handling as “shoddy” while the former permanent secretary at the Home Office, Philip Rutnam, told Newsnight that “an end to this kind of corrosive negative briefing…would be the single biggest thing this government could do to improve the effectiveness of the civil service in the short run and the long run”.

At the time of his appointment, the PM said Sir Chris would be tasked with “the complete re-wiring of the British state to deliver bold and ambitious long-term reform”.

Three days before he gave Sir Chris the job, the PM accused “too many people in Whitehall” of being “comfortable in the tepid bath of managed decline”.

So a year or so on, he must feel the Civil Service has not yet been given the short sharp shock of an invigorating cold shower he thinks it needs.

At the moment, the smart money is on Dame Antonia Romero – the current permanent secretary at the Home Office – getting the top job.

If appointed cabinet secretary, Dame Antonia is not a civil servant who would hide in the shadows and her supporters say she is a “disrupter” who can challenge Whitehall orthodoxy.

She could also be appointed quickly having been shortlisted the last time the role was advertised.

But in the wake of the Mandelson affair attention will be focused on the “due diligence” process ahead of any appointment.

Insiders seem confident that extensive vetting must have been done before Dame Antonia was given the top civil service job in the Home Office.

But her former boss that the Foreign Office, Lord McDonald told Channel 4 News , externalthat if she was indeed the favoured candidate “the due diligence has some way still to go”.

This has been interpreted as a reference to an investigation Dame Antonia faced over allegations about her spending in 2017 when she was the government’s consul-general in New York.

The Cabinet Office has said this had come from a single complainant and that an investigation had found no case to answer.

Dame Antonia’s supporters believe some of the criticism she has received in the media is motivated by sexism.

Either way, this could be the first test of the beefed-up vetting processes promised by Sir Keir in the wake of the Mandelson controversy.

For someone who promised stability, the PM could ill-afford to lose what would be the third head of the UK civil service since he took power in July 2024, having initially inherited Cabinet Secretary Simon Case from the previous administration.

But some of Starmer’s own MPs believe what is going wrong is not so much process as political direction – or lack of it.