Why Britain resists adding a dedicated Osprey tanker fleet

Does the Royal Navy need Osprey aerial tankers for the F-35B?

The capability is useful, but a separate small fleet is too expensive; a future common medium-lift aircraft is more plausible.

An Osprey tanker would extend F-35B range more effectively than a Merlin conversion. Britain would probably wait for the next generation of medium-lift vertical-takeoff aircraft rather than introduce a tiny specialist Osprey fleet. A separate type would require its own training, maintenance, and support organization while duplicating troop-lift work already performed by Merlin. British force design instead favors a larger common fleet that can cover several missions and eventually add tanker capability without multiplying small aircraft communities.