The UK Ministry of Defence (MoD) has reportedly allocated funding and will negotiate with the US JSF Program Office (JPO) for 26 more F-35B Lightning II combat aircraft.

The UK is already committed to 48 F-35Bs which are due to be fully-delivered by 2025 and are operated by joint RAF and Royal Navy aircrews, and has a program-of-record for up to 138 F-35s which originates to when it joined the JSF program in the late 1990s as a Tier 1 partner. The additional 26 jets will give it a fleet of 73 F-35Bs, after one was lost in a take-off accident from HMS Queen Elizabeth in 2021.

While there was some conjecture that the UK would order some conventional take-off and landing (CTOL) F-35As, the additional 26 aircraft being sought will all be F-35Bs. Deputy Chief of the Defence Staff, Air Marshal Richard Knighton reportedly told a parliamentary committee that, “the decision around further purchase beyond that 74 will be taken in the middle of the decade in the context of what we decide to do on our Future Combat Air System [FCAS] programme,” adding that, “It’s perfectly plausible we have a fleet of 138 as we described back in the early 2000s.”

A fleet of 74 jets will allow the RAF to operate three front line squadrons from land bases and the Royal Navy’s two Queen Elizabeth class carriers, and an operational evaluation unit, with 15 aircraft assigned to each unit and a maintenance and attrition reserve of 12-16 jets.