Sir Mark Sedwill has announced he will stand down from his role as cabinet secretary, national security adviser and head of the civil service in September.
The move will be seen as a victory for Dominic Cummings, Johnson’s most senior aide, who has had a tense relationship with Sedwill. Sources said Cummings believed Sedwill was a barrier to Whitehall reform and has been backed by Johnson and Michael Gove, the Cabinet Office minister.
But the news has been met with concern from former mandarins who are worried that the government is trying to politicise the civil service.
His exit from No 10 is likely to be part of a wider shake-up of the civil service overseen by Cummings and Gove.
Whitehall sources said the prime minister would use his departure to split the roles he has been performing into separate positions. No 10 declined to respond to questions asking whether Sedwill would stand down.
Sedwill, 55, the cabinet secretary since 2018 and national security adviser since 2017, has told friends that he has been angered by negative briefings over many months.
Unnamed Downing Street sources claimed that he had failed to get a grip on the coronavirus crisis. Another source was quoted as saying that he had fallen out with Johnson and his aides over the response to the virus. In April, Cabinet Office insiders said the claims were “shit-stirring” and “absolute crap”.
As cabinet secretary, he was supposed to coordinate the work of permanent secretaries as they grappled with lockdown, PPE supplies, food supplies, prison releases and coronavirus tests.
Sedwill, who attended cabinet and Cobra meetings, fell ill with the virus soon after Johnson, Chris Whitty, England’s chief medical officer, and Matt Hancock, the health secretary. He informed the cabinet when the prime minister was moved to an intensive care unit.
Whitehall officials said several candidates were being mooted to replace him, among them Tim Barrow, the UK’s ambassador to the EU. The Financial Times has claimed that David Frost, the prime minister’s Brexit adviser and a former diplomat, is likely to take over his national security job.
Alex Ellis, currently the deputy national security adviser, could replace Sedwill temporarily while Frost conducts the Brexit trade negotiations.
Occasionally abrupt, Sedwill has made enemies in government. The education secretary, Gavin Williamson, was sacked from his previous job as defence secretary after Sedwill led a probe into a leak from the National Security Council and concluded that Williamson was the source.
Some senior civil servants have claimed that he has failed to back the Home Office’s former permanent secretary Sir Philip Rutnam in the ongoing row over allegations that the home secretary, Priti Patel, has bullied staff.
Sedwill was born and grew up in Lincolnshire, attending Bourne grammar school. He studied international economics at the University of St Andrews and has a master’s in economics from St Edmund Hall, Oxford. After joining the Foreign Office in 1989, he had postings in Afghanistan, Egypt, Iraq and Pakistan.
Patel said on Sunday that significant Whitehall reforms would soon begin. “This is the people’s government, delivering on the people’s priorities, and effectively any reforming government will be based around the type of delivery that our prime minister wants to drive for our great country and obviously have the right kind of support around him to deliver that,” she told Sky News.
Gove set out his manifesto for reforming the civil service on Saturday in a lecture with the title The Privilege of Public Service. The Cabinet Office minister said the “metropolitan” outlook of decision-makers had contributed to the government becoming “estranged” from the people.