The Swanwick air traffic control company Nats have issued a statement about the flight restrictions covering the South.
We are experiencing technical problems at our Swanwick control centre and we are working to restore full operations.
This has not resulted in the closure of UK airspace or the suspension of all flights in or out of the UK.
However, to maintain safety, we are restricting the number of aircraft flying across the south of England and those taking off from airports. We regret any inconvenience this may cause; however, our first priority will always be the safety of the flying public.
We are taking every step to restore services and have contingency plans."
Air traffic controllers at Swanwick in Hampshire are bracing themselves to cope with an extra 4,000 flights this summer because of the Olympic Games. Airspace will be restricted to private planes, hot air balloons and microlights for a month from July 16.