The project was cancelled due to changes in market requirements that also led to the development and production of the smaller but similar Rolls-Royce Spey, and the cancellation of the Armstrong Whitworth AW.681 military transport aircraft project.

[1] As a considerable amount of company funds had already been spent on development, the project was continued to rework the design for another future aircraft project, the Armstrong Whitworth AW.681 VTOL military transport aircraft.

The rear section of the engine was modified to incorporate an internal thrust deflector to duct exhaust gases through swivelling nozzles; an idea similar to that used on the contemporary Bristol Siddeley Pegasus.

Cancellation of the AW.681 project however also brought to an end further development work on the Medway with attention turning to the smaller, but very closely related, Spey turbofan, the Spey being basically a scaled-down Medway incorporating more recent technical developments.

[2] Another possible application for the Medway was the Saab 37 Viggen, but a lack of British government funding was stated as the reason for the cancellation of this order.