Britain's Royal Air Force will be on standby to to shoot down any rogue aircraft under tight new restrictions being enforced two weeks ahead of the Olympic Games.
New airspace restrictions coming into force in London on Saturday impose prohibited zone in a 50km radius of the capital.
Commercial aircraft will still be able to use defined corridors, but any planes flying close to the Olympic Park are at risk of being shot down, the ABC reports.
"As a last resort, we will have lethal force as an option," said Stuart Atha, the Olympics air security commander.
He said any decision to down planes would be taken by "the highest level of government".
The fighter jets are being deployed in London for the first time since WWII.
Last week, a group of east London tenants lost their High Court battle to prevent missiles being stationed on their roof during the Games.