Harmondsworth IRC, Heathrow

The Harmondsworth site has held people under immigration powers in various forms since 1970. After 2006 disturbances destroyed two wings, the site was rebuilt to Category B prison standard. The opening of two new wings in 2010 made it formally the largest immigration removal centre in Europe. Mitie has held the joint Heathrow IRC contract covering Harmondsworth and Colnbrook since September 2014^[4]GOV.UK.

Inspectors visited Harmondsworth between 12 and 29 February 2024 and published their report on 9 July 2024. They reported decrepit accommodation, doubled assault rates compared with the previous inspection, widespread drug use, numerous serious suicide attempts, and staff who largely kept to offices with do not enter signs across their doors. Home Office leaders had sanctioned the closure of one dilapidated wing for refurbishment, but another equally decrepit unit remained in use^[2]GOV.UK. A subsequent review of progress recorded substantial improvements after staff levels were doubled and refurbishment work began^[1]GOV.UK.

At an indicative IRC bed-day rate of £350, the 676 places at Harmondsworth imply an annual operating run-rate of roughly £86 million if fully utilised. The May 2025 NAO accommodation report tracked detention costs separately from the £1.296 billion asylum hotel bill but identified detention modalities as among the most expensive options for the public purse^[5]NAO.