Britain’s next-generation Tempest fighter jet programme is facing delays, raising concerns of a diplomatic rift with Japan and Italy, after the UK postponed signing a key trilateral contract.
Ministers had previously vowed to conclude the agreement for the multibillion-pound Global Combat Aircraft Programme (GCAP) by last year, but the UK is now waiting for the Ministry of Defence (MoD) to finalise its Defence Investment Plan (DIP) before committing to the next phase.
The postponement comes amid reports that Prime Minister Sir Keir Starmer expressed concerns over a £28bn budget shortfall up to 2030, prompting defence chiefs to revise spending proposals. Industry sources warn that the delay could jeopardise the programme’s ambitious goal of delivering combat-ready jets by 2035.
Industry officials say progress on Tempest continues using existing national funding streams, but UK contributions are expected to run out within months, leaving the programme vulnerable.
One source noted: “We had previously been told the funding for GCAP was ring-fenced – but it now seems to be tied up with the DIP. The Japanese and the Italians are not happy.”
The Japanese government declined to comment on the causes of the delay but said it is working with the UK, Italy, and Edgewing, the joint venture leading programme delivery, “to finalise an agreement at the earliest possible timing.”
The GCAP, formally signed under an international treaty in 2022, aims to develop a sixth-generation stealth fighter, alongside supporting “loyal wingman” drones and dedicated software systems. The UK has committed £2bn so far, with the MoD projecting a total UK contribution of around £12bn over a decade. Italy’s estimated costs have reportedly tripled to €18.6bn (£16.2bn) since 2021.
The Tempest jet is intended for long-range operations, capable of penetrating enemy airspace, neutralising air defences, and acting as a communications hub for allied forces.
The next funding tranche, originally expected by September 2025, would have provided billions of pounds to Edgewing for development and procurement. Delays to the DIP have further pushed back the contract, with a new deadline now uncertain.
Defence Secretary John Healey told MPs he remains “absolutely determined that the momentum of the programme is maintained,” but offered no timeline for finalising the contract.
Shadow Defence Secretary James Cartlidge criticised Labour’s handling of defence spending, stating: “This is itself the result of Labour’s decision to prioritise spending on welfare instead of defence, resulting in paralysis and indecision.”
The delays are particularly sensitive for Japan, which is seeking a rapid development timeline in response to an assertive Chinese military presence in East Asia. Tokyo has reportedly opposed suggestions that Germany join GCAP as a top-tier partner, fearing further setbacks.
GCAP development continues using staff seconded from partner companies including BAE Systems, Rolls-Royce, Leonardo, and Japan Aircraft Industrial Enhancement, though procurement decisions cannot yet be made without new funding.
Independent defence analyst Francis Tusa commented: “This is our international reputation. Asking Japan and Italy to ‘wait a bit’ is frustrating and does not reflect well on the UK.”
