The Ministry of Defence’s top civil servant David Williams will be stepping down in the autumn.
Mr Williams, who is the permanent secretary at the MoD, announced his departure just weeks after it was revealed the government had put up to 100,000 lives at risk though a catastrophic data loss.
His departure is part of a bid to bring fresh leadership to senior defence roles, The Independent understands.
An MoD spokesperson said: “Permanent Secretary David Williams will step down this autumn and the recruitment process for his successor is under way. Since 2021, David has led the department through a period of significant activity, and we thank him for his contribution.”
Mr Williams has been in the position for four and a half years and it is understood his departure is not related to the Afghan data leak, which resulted in an unprecedented MoD superinjunction.
A new chief of defence staff, Air Chief Marshal Sir Richard Knighton, will also take up his appointment in September this year.
Last year defence secretary John Healey pledged to fix the broken defence procurement system through new reforms.
A “root and branch” defence review also reported in June this year, looking at everything from equipment to future threats.
In response prime minister Sir Keir Starmer ordered up to a dozen new attack submarines, £15bn worth of investment in the nuclear warheads programme and thousands of new long-range weapons after the report concluded that the country should prepare for war.
The strategic defence review also called for a small rise in the size of the regular army “as a priority”, although the defence secretary said this would not happen before 2029 at the earliest.
It also recommended that the UK should have a minimum of 100,000 soldiers, ministers should hike the number of active reservists by 20 per cent, and that government should slash the civil service defence workforce by 10 per cent.