Pilots who stray too close to Olympic sites will be shot down, a top officer confirmed today as soldiers activated eight sets of surface-to-air missiles.
Air Vice-Marshal Stuart Atha said that in a "worst-case scenario" a squadron on Typhoon fighter jets and sniper-carrying Puma choppers would take to skies and shoot down pilots that failed to identify themselves or change course when ordered.
"As a last resort, we will have lethal force as an option."
Commercial flights are allowed to continue as normal within the "restricted zone" over London but general aviation - including light aircraft, gliders and balloons - will be affected.
The aerial defence operation has been the centre of fraught debate in recent months, with east London residents pointing out that any aircraft would come down straight on top of them.
Nick Wood, a local campaigner who lives in Tower Hamlets' Victoria Park, told the Morning Star that the plan frightened him.
"That's not protecting anybody - it's just moving the dead."
The anger has focused largely on a network of six surface-to-air Rapier missiles and two high-velocity missiles - also described by defence officials as a "last resort" - that are sited in some of Britain's most densely populated areas.
The Rapier missiles, with a range of 7km, are stationed in a ring around the Olympic stadium with sites on Blackheath Common, Oxleas Wood, William Girling reservoir in Enfield and Barn Hill at Epping Forest's Netherhouse Farm.
The high-velocity missiles are rigged atop two blocks of flats: Bow Quarter's Lexington Building in Tower Hamlets and the Fred Wigg Tower in Waltham Forest.