London mayor Sadiq Khan has blocked a £50m Met police deal with Palantir, citing "clear and serious breach" of procurement rules. Khan's office withheld approval, claiming Scotland Yard engaged with only one supplier and risked becoming locked into the US company's technology. The mayor emphasized that public money should go to companies sharing London's values.

Palantir, co-founded by Trump-supporting tech billionaire Peter Thiel, already holds £600m in UK public sector contracts, including with NHS, Ministry of Defence, and several police forces. The company has faced rising political and public criticism for its work with ICE operations and Israeli military, despite its AI being credited with helping bring down organized crime.

The Met previously used Palantir's AI in a staff monitoring trial that led to hundreds of officers being investigated for misconduct. Khan's decision presents a setback for the Labour government's £115m AI policing strategy. The mayor plans to raise whether ethics should be considered in public procurement processes, while Mopac indicated willingness to work on a new procurement process.