Air travellers in the UK face severe disruption this morning following computer problems at the National Air Traffic Service (NATS) at Swanwick in Hampshire.

Flights leaving London Heathrow, Gatwick and some other regional airports in England have been hit by the outage.

A spokesman for Heathrow said: "We are restricting departures to give priority to arrivals."

This latest problem to dog NATS appears to centre on a software upgrade to computer terminals carried out last night.

Although the upgrade reportedly went well, at around 6.30 this morning air traffic operators found that half the radar work stations went on the blink.

A spokesman for NATs told The Register: "We carried out a routine upgrade of software at Swanwick last night. It all went to plan.

"About 6.30 this morning we found we could only operate around half the radar work stations. It meant we had to reduce capacity by 50 per cent."

Engineers are currently working to resolve the problem.

Travellers are being advised to check with airlines about posiible delays and canellations. ®