For almost 80 years, RAF Brize Norton has been one of the country’s most important military airfields, serving as an embarkation point for members of the Royal family and senior politicians as they fly around the globe.

So one could be forgiven for expecting security around the Oxfordshire airbase to be watertight.

In reality, however, things are a little more porous, with sections of the eight-mile perimeter protected only by a six-foot wooden fence that would not look out of place surrounding a suburban garden.

In the early hours of Friday morning, two members of the protest group Palestine Action – which will now be proscribed as a terrorist organisation – took advantage of the seemingly lax defences to enter the airfield and attack two military aircraft.