A department within London mayor Sir Sadiq Khan’s office unlawfully blocked a £50 million between Metropolitan Police and technology firm Palantir “because of an alleged mismatch between Palantir’s ‘values and ethics’ and ‘London’s values’”, High Court documents claim.
Palantir, founded by tech magnate Peter Thiel, is suing the Mayor’s Office for Policing and Crime (Mopac) after it refused to approve the deal earlier this year.
The Met had sought approval to implement artificial intelligence technology to automate intelligence analysis in criminal investigations. Similar AI technology is already in use by other police forces, the NHS, and the Ministry of Defence.
However, Mopac blocked the move, claiming that Palantir was the only supplier the Met had seriously considered for the proposed contract. Mopac claimed the force failed to present its procurement strategy for approval, describing this as a "clear and serious breach" of procedure, which prevented City Hall from ensuring value for money.
After the decision in May, the force warned that it would have to reduce officer numbers, with Palantir’s UK chief executive claiming Sir Sadiq was “putting politics over public safety”.
Palantir then filed a legal claim against Mopac at the High Court in June, with lawyers for the company claiming in court documents that it is seeking “a declaration that (Mopac) has acted unlawfully, an order quashing the decision, and an order that the contract be awarded to the claimant”.
Mopac, which is due to file defence to the claim later this month, has said it will oppose the action.
At a preliminary hearing on Thursday, Mr Justice Constable said that a full hearing in the case would take place in January next year.
In court documents setting out Palantir’s claim, Lord Pannick KC said that the Met approached the company about the contract in April, and understood that it had been selected as the supplier by May.
But Lord Pannick said that press articles on Mopac’s refusal to approve the deal cited concerns about Palantir’s values and ethics.
These included a Guardian article in April quoting a spokesperson for the Mayor of London’s office who said: “As a general point, the mayor would have concerns about using public money to support firms who act contrary to London’s values.”
The barrister also said that in June, the Met said in a public response to Mopac’s decision that it “made best endeavours to repeatedly engage (Mopac)” throughout the procurement process, and that Palantir offered the only “viable service offering capable of meeting the specific requirements” of the contract.
He continued that Mopac’s assessment of Palantir’s “values and ethics” had played an “unlawful and non-transparent role” in the decision-making process, claiming that Mopac has “not acted transparently in disclosing the correct or complete reasons for the decision”.
Lord Pannick said that the “irrelevant consideration” of Palantir’s supposed values and ethics was a “manifest error” and meant that Mopac unlawfully discriminated against the company while introducing an “unlawful veto”.
He continued that this meant the decision was “irrational, disproportionate, and is based on irrelevant considerations”.
He also said that Mopac’s claim that its decision was based on the Met not informing it of the force’s procurement strategy and that the deal did not represent value for money was “manifestly erroneous”.
He said: “It is… inherently implausible that the selection of Palantir as the ‘best, and/or most economical’ supplier was incorrect: the Met has adopted a robust and effective process, advised by specialist procurement lawyers and consultants.”
A spokesperson for the Mayor of London said: “On May 21 2026, the Deputy Mayor for Policing and Crime declined approval for the Met to award a contract worth up to £50m with technology firm Palantir to deliver a system called Unified Operational Analytics.”
“This decision is subject to legal challenge.
“We continue to robustly defend this decision, made in line with our statutory responsibilities.”
