A total of 357 outbound flights have been cancelled or did not fly today, aviation analytics firm Cirium has said.

However, it did say cancellations appear to be slowing now.

More than 2,000 flights have been impacted altogether.

Here’s a breakdown by airport:

One passenger wrote on social media: “Can't believe Ryanair won't offer compensation on our flight from Nice to Stansted which was delayed by 4 HOURS

“It was caused by air-traffic control issues, but a delay of 4 hours significantly impacts other travel plans/bookings at the arrival end.

“Surely that's not right?’

Hundreds of thousands of passengers hit by the flights chaos in Britain are unlikely to be able to get compensation, the CAA has said.

They might have expected to get payouts of £520 for delays to their journeys.

But airlines are unlikely to have to pay out as the incident is expected to be put down to the result of ‘extraordinary circumstances’ under passenger rights rules.

A UK Civil Aviation Authority spokesperson said: “We know many passengers have faced significant disruption and frustration following the NATS system issue on Tuesday, 8 September, and we understand the impact this has had on their travel plans.

“As part of our established regulatory framework, NATS will be providing a technical report on the incident shortly. In addition, the Government has asked the UK Civil Aviation Authority to carry out an independent review of the disruption to establish what happened and consider how well NATS is set up to deliver a resilient service in the future.

“In the meantime, we have reminded airlines of their responsibilities to look after passengers whose flights have been delayed or cancelled. We consider that disruption caused by the NATS outage is likely to be considered the result of ‘extraordinary circumstances’ under passenger rights rules. This means that although passengers should be looked after by airlines, they are unlikely to be entitled to compensation for delays or cancellations that were directly caused by the incident.”

An American family caught up in the travel disruption today said they joined a queue to speak to a member of staff about the status of their flight, only to be told the customer service staff there couldn’t help.

"There were really long lines for an information booth that we stood in for a couple of hours and when we got up in the front they finally said they can't help you when you get there,” father Bob Sehl said.

The family’s Santorini to Heathrow flight was originally diverted to Stansted, which doesn't operate BA.

This meant that at 2.30am, more than 10 hours after landing, they had to travel to Heathrow to try and continue their homeward journey to Connecticut.

The family say they now face a night sleeping on Heathrow’s floor as all the local hotels have been booked up.

An American woman has said it is “nerve-racking” to wait in departures without a gate number after her planned route to Warsaw was cancelled.

Jennifer Jones, 69, is on a layover at Heathrow from Phoenix, Arizona, and said: “(We) had to wait on the plane for the bus to come get us because everybody was trying to get on the buses, so we finally got on the bus and got inside, and it was chaos because everybody’s flights were cancelled, and by the time we figured out ‘well, I’m going to have to stay the night’, the hotels were all booked.”

She landed at about 3pm, found a hostel that she arrived at at about 9pm, and then returned to Heathrow at 2.30am “hoping to get another flight so I don’t miss any flights to Warsaw”.

Perched on a luggage trolley, Ms Jones, who has had her trip to Warsaw with her friends booked for about a year, added: “In the States you go to the airport and you just take your boarding pass and go through security and go to your gate and then you sit there and guard your plane, you know, and here you don’t even have a gate assignment so you can’t get through security yet – that’s a little nerve-racking.”

Airlines UK has written to the Secretary of State for Transport, Rt Hon Heidi Alexander MP, to register serious concerns over yesterday’s technical failure at NATS.

It marks the third major system failure in three years which has caused major disruption across the UK’s aviation network.

Tim Alderslade, CEO of Airlines UK, said: “The latest NATS failure has again exposed a gap in the UK’s aviation regulatory framework. Airlines are expected, in supporting passengers, to absorb the costs of disruption, even when the cause lies entirely outside their control.

“The result is a system where airlines pick up the bill for the mistakes of others, while the organisations responsible face little or no financial consequence. Accountability should sit where responsibility lies and the Civil Aviation Bill offers the opportunity to address this.”

British Airways said it has “long made the case for improved resilience in aviation” and issues raised by the system failure need “to be addressed as a matter of urgency”.

A spokesperson said: “We’ve heard reassurances before, but then we’re faced with issues like this yet again.

“Our customers and colleagues are tired of dealing with these issues, time after time. This needs to be addressed as a matter of urgency.

“Over the coming days, we’ll continue doing everything we can until every affected customer is on their way.”

BA staff volunteered to work at its call centres and flying operations, and on Wednesday the airline plans to operate a full long-haul programme out of Heathrow and a full operation from Gatwick, it is understood.

Tuesday’s air traffic control issue forced British Airways to cancel nearly 550 flights – affecting 85,000 of its customers.

A total of 349 were axed on Tuesday and a further 200 cancelled on Wednesday. The airline diverted 17 journeys to different airports.

A BA spokesperson said: “Since yesterday, we’ve rebooked more than 60,000 customers to travel on alternative flights, getting them to their destinations as quickly as we can.

“Today, we’ve been able to operate almost 80% of our schedule across our whole network.

“We know this has been a very challenging and frustrating time for our customers, and we’re incredibly sorry for the experience they’ve endured because of an issue that has been entirely out of our control.

“The scale and challenge of dealing with the aftermath of an event like this is severe and complex.

“What this and previous disruption events highlight is the enormous impact customers suffer when one part of the aviation system fails.”

London’s airports were the hardest-hit by the air traffic control glitch on Tuesday, suffering the highest volume of ground stop orders, delays and flight cancellations.

Thousands of passengers have been affected by the issue, with many reporting hours-long delays.

As of 4pm on Wednesday, the number delays and cancellations at Heathrow and Gatwick were as follows, according to FlightRadar:

A total of 2,093 flights have been affected by the Nats technical issue since Tuesday, according to Cirium.

The figure represents 5.91 per cent of the 5,869 scheduled flights.

A normal day is between one and two per cent.