Heathrow and Gatwick among airports hit by air traffic control problems

Flights from airports in the UK and Ireland are being heavily disrupted by a technical problem affecting the air traffic control provider Nats.

At least 425 flights in or out of the UK have been cancelled, according to tracking website FlightRadar24. EasyJet and British Airways have cancelled more than 100 each.

Nats said just before 17:00 BST that its flight systems were starting to recover.

With few aircraft able to take off, it is understood landings are being restricted, leading to some flights being prevented from departing from overseas airports.

At Heathrow, departures were initially paused around lunchtime. Traffic then resumed, before facing further disruption in the afternoon. It is understood that very few flights are currently taking off. BBC News understands that no flights were going in or out of the airport at 17:00 BST.

Passengers have been advised to contact their airlines to check the status of their flights.

Gatwick said it was currently being affected by the issue, along with other airports.

East Midlands has also been affected, while Manchester Airport warned that some departing flights could be delayed. Passengers have been advised to contact their airlines to check the status of their flights.

Belfast's two airports have both advised passengers to check flight information. The City of Derry Airport said it had experienced some cancellations and delays.

Nats said on Tuesday afternoon that engineers were on site, and it was "working urgently to resume normal operations as quickly as possible".

The organisation apologised for the delays caused and advised passengers to check the status of their flight with their airline. Nats said it would provide updates on and X.

Transport Secretary Heidi Alexander said she was aware of the situation, and realised it would be frustrating for passengers.

According to Nats, the flight processing system processes flight plans and other operational information used by air traffic controllers to manage air traffic.

The system continually updates flight information as aircraft progress through UK airspace, helping controllers maintain a safe and orderly flow of traffic.

British Airways said in a statement on its website that passengers should travel to the airport as normal if they have not been contacted by the airline directly. It added that the situation was "entirely out of our control".

Ryanair said affected passengers would be notified.

Phil White from Bexhill told BBC Your Voice that his flight to Lanzarote boarded on time but has been sitting on the tarmac at Gatwick for hours.

"We've been told the radar is down and we can't take off," Phil said.

"It's comfortable enough but the pilots been on every 20 minutes saying they are waiting for information from air traffic control and when he finds anything out he will let us know."

Edinburgh Airport said in a post on X that the issue might affect its operations, while Dublin and Cork airports in Ireland are also experiencing delays.