An American family face another night sleeping on the floor of Heathrow Airport as they desperately try to return home to the US amid chaos at UK airports.

It comes after a technical issue with the UK’s traffic control system yesterday caused disruption for more than 600,000 passengers across the country, with hundreds of delays and cancellations at London airports.

Passengers reported hours-long queues while stuck on the tarmac last night, some claiming they had gone hours without food or drink, while others waited around airports for updates on the status of their flights.

For one American family-of-four, the disruption has turned their journey home into an airport ordeal.

Their Santorini to Heathrow flight was diverted to Stansted - which does not operate British Airways.

As a result, at 2.30am, more than 10 hours after landing, they had to travel to Heathrow to try to continue their homeward journey to Connecticut.

But their flight back to the States does not depart until at least 4.30pm on Thursday.

The family have used towels for cushions and luggage trolleys for seats and were one of many groups waiting with their luggage at Terminal 5 departures on Wednesday.

Father Bob Sehl said: “We were three-quarters of the way, a little bit more, to Heathrow when everything shut down and they derailed us (to Stansted).”

The family then had to wait five hours for their luggage at the Essex airport, with Bob adding: “We just waited and waited and more people and more people came and it just became a real crowded nightmare.”

In classically British fashion, they joined a queue to speak to customer service agents at the London airport - only to be told after two hours that the staff there could not help.

Bob said: “There was 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.

“We finally asked questions when we got further up in the line and realised you have to do everything over the phone, which the little card they gave you with the phone number didn’t work.”

In a further blow, the family say all the hotels have been booked and they now face a second night sleeping on Heathrow’s floor.

“We know it’s not (British Airways’) fault, it happens, but it would’ve been nicer for them to be more proactive with helping us”, Bob said.

Other passengers also face sleeping on airport floors, with one couple reporting that they did not want to pay the money for a hotel due to the cost and fears of missing replacement flights in the morning.

Jennifer Jones, 69, is on a layover at Heathrow from Phoenix, Arizona, said the situation yesterday was “chaos”.

She found a hostel at around 9pm and returned to Heathrow at 2.30am today.

Perched on a luggage trolley, Ms Jones, who has had her trip to Warsaw with her friends booked for about a year, said: “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.”

British Airways, one of the airlines worst affected by the technical outage, has had 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, while 17 journeys were diverted to different airports.

The airline said issues raised by the system failure needed 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.

Despite the ordeal, Mr Sehl added that the travel chaos would not stop the family from coming to England again.