Britain and Japan set to merge military fighter programmes costing ‘tens of billions of dollars’, sources say
- It would be the first time Japan has sought a non-US partner for a large military programme and its first major collaboration with Britain
- Deeper ties between the two allies come as London takes a bigger military role in Asia, while Tokyo is strengthening its hand against China

Britain and Japan are close to an agreement to merge their next-generation Tempest and F-X fighter jet programmes, with the two countries aiming for a deal on a new joint project by year-end, three sources told Reuters.
It would be the first time Japan has sought a non-US partner for a large military programme and the first major collaboration between Tokyo and London, going beyond what had been expected when industrial talks began five years ago.
“This would be an equal partnership between Japan and Britain,” said one of the sources with knowledge of the plan. It will cost tens of billions of dollars, he added.
The push to combine the Japanese F-X programme, led by Mitsubishi Heavy Industries (MHI), with Britain’s Tempest, managed by BAE Systems PLC, by December has not previously been reported.
The sources asked to remain anonymous because they are not authorised to speak to the media.
“The main thing that we are aiming for is to build a common jet, that may have small differences in design for each country,” said another of the sources.