The new National Security Advisor David Frost will be a political appointment - which a former head of the Civil Service said left him 'worried'

Critics have accused Downing Street insiders of targeting the UK's top civil servant with "hostile briefings" and blaming him for mistakes made during the coronavirus pandemic.

Cabinet secretary had been at odds with Dominic Cummings and a target of hostile briefingsRelationship with No 10 was no longer tenable

Unlike previous holders of the National Security Advisor job, David Frost is a political adviser rather than a career civil servant and lacks security experience

Former officials question David Frost’s suitability for role as neutral adviser

Sir Mark Sedwill has announced he will stand down from his role as the UK's top civil servant.