The Zephyr UAV will eventually stay airborne for 90 days.

It has been described as a potential "game changer" in the battle against extremists in Iraq and Syria.

Makers of The Zephyr, Airbus, claim it "endures like a satellite, focuses like an aircraft and is cheaper than both of them".

A model was on show at the Defence and Security Equipment International show at ExCel in London and members of the Royal Corps of Signals have put it through its paces.