The Boeing aircraft was urgently rushed into service with emergency Treasury funds, but these will dry up next year with no money found for a new generation. The cuts mean the Navy is now expected to be without ship-based drones for at least two years, sources said.

The ScanEagle, which has cost around £60 million, is launched from a deck catapult and can stay aloft for up to 10 hours, beaming back footage to the frigate.

In 2014, Philip Hammond, then Defence Secretary, said it would “play a crucial role in operations and humanitarian missions not only in the Gulf but also on Royal Navy vessels right across the globe, further underlining our commitment to invest in innovative capabilities”.