The Cabinet Office’s headcount has dropped by 13% in one quarter, according to new data from the Office for National Statistics.
Public sector data for December 2025, published by the ONS this morning, shows the department’s full-time equivalent headcount – which doesn’t include its arms’-length bodies – dropped from 6,190 to 5,390 from September to December 2025, a decrease of 800.
It comes after the department launched voluntary exit and mutually agreed exit schemes in January and March last year. The Cabinet Office also announced in April 2025 that it intended to reduce the size of its core workforce by a third over the following two years, eyeing up cuts of around 1,200. At that point, more than 500 voluntary exit scheme applications had already been supported by the department.
The voluntary exit scheme was completed in October 2025 with staff leaving employment by the end of last year, CSW understands.
The staff reductions form part of the Cabinet Office's plans to make cost savings of over £110m by 2028, achieved by making efficiencies through the better use of AI and technology and closing down non-essential programmes.
A Cabinet Office spokesperson told CSW: "The Cabinet Office Futures programme was announced last year, to restructure and reorganise the Cabinet Office, making it more specialist, more strategic and smaller.
"We are prioritising frontline delivery, putting more money into putting more police on the streets, teachers in our children's classrooms and nurses in the NHS."
While the Cabinet Office’s FTE headcount has fallen significantly, the overall civil service numbers have slightly increased, rising from 520,000 to 521,000 over the same period. This is largely driven by HM Revenue and Customs.
At the 2025 Spending Review last June, HMRC was given £1.7bn over the current SR period to fund 5,500 extra compliance staff and 2,400 debt management staff.
Since then, HMRC’s FTE headcount has risen by 3.5%, going up from 65,995 in June 2025 to 68,290 in December 2025. The department increased its numbers of permanent and temporary staff by 1,060 and 130 respectively between June and September last year, while today’s data update shows permanent and temporary FTE headcount went up by a further 1,235 and 180 between September and December.
An HMRC spokesperson told CSW: “The government is investing more than £1.6bn over the next five years for HMRC to recruit 5,500 additional compliance staff and to fund 2,400 debt management staff which will help close the tax gap and secure billions more in revenue, ensuring the tax that should be paid is paid. We are on track with recruitment, surpassing the 2025–26 target of 1,100 additional compliance staff.”
The debt management funding enables HMRC to retain 1,200 current debt management staff until March 2030 and to recruit a further 1,200. The department expects most of the recruits to join by the end of 2026-2027.
The civil service’s ranks have increased every year since 2016, with growth driven by the demands of the UK’s decision to leave the EU and the need to respond to the Covid-19 pandemic, and various drives to reduce the overall size of the civil service failing to land.
The ONS public sector employment release includes data going back to 1999, when the FTE headcount was around 475,000. Under Tony Blair, it rose to a high of 534,000 in 2004, and then fell over his final three years as prime minister to 500,000, before dropping to 481,000 during Gordon Brown's short tenure as PM. The coalition government's austerity-driven attempts to rein in numbers saw a much more significant fall in FTE headcount, reaching a low of 384,000 in June 2016, the month of the Brexit referendum.
The current FTE figure of 521,000 in December 2025 is a 36% increase on the June 2016 numbers and just 13,000 shy of the 25-year high in 2004.