More than 24,000 people have already been affected, but the operator of the Channel Tunnel passenger trains admitted it could not give a guarantee of when services would resume.

Eurostar will send test trains along the route on Sunday to see if they can withstand the sub-zero temperatures in northern France which are believed to have caused five trains to break down in the tunnel on Friday.

Eurostar’s executive director Richard Brown said: "I can’t guarantee our services will be working because we’ve suspended the service again today until we get to the bottom of what happened on Friday night.

"We did run two or three trains yesterday, they all got through the tunnel OK, but one or two of them showed symptoms of the problem that happened on Friday night.

"We will not start services again until we’re sure that we can get them through safely," he told BBC television.

More than 2,000 passengers spent Friday night trapped in the Channel Tunnel, some without anything to eat or drink, in stuffy conditions.

Angry passengers have accused the company of handling the situation badly.

Brown admitted it had taken a "very long time" to evacuate people from the trains.

"Clearly, if you’re on a train stranded in a tunnel, it is a distressing experience," he said.

"People will panic," he added, which was why the contingency plan was to get the trains out of the tunnel, with the passengers still on board, as soon as possible.

"That’s what went wrong, it took too long to get the trains out."

And although the trains had been carrying spare water supplies, that had run out, he said.

"I’m not saying it went well, I’m saying it went rather better than actually a lot of people say."

Thousands of people were left stuck at Eurostar terminals in London and Paris on Saturday, as they desperately sought information on when they could catch a train.

Musician Frank Turner was one of those hit by the Eurostar suspension — when he discovered it would be impossible to travel on Saturday, the singer-songwriter paid 500 pounds (570 euros, 800 dollars) for a business class flight from Paris to Heathrow Airport in order to play a concert in London.

He said: "I had moments where I considered giving up, but I had to do it. It’s been a nightmare, and has been incredibly frustrating, but it’s one of those situations where there’s no one you can shout at."

Passengers who have suffered delays will be offered a full refund of their ticket, a free return ticket, and 150 pounds per person.

Eurotunnel, which operates a cross-Channel drive-on train service for cars and trucks, said its services for cars were running on Sunday, but with delays.

The situation was worse for lorries, which were being held on the motorway leading to the Eurotunnel terminus in Folkestone, southeast England.

The disruption in the Channel tunnel is the worst since a large fire on a Eurotunnel train in September 2008 caused a two-day suspension of services — but that did not take place during a particularly heavy holiday travel period.

The problems with the Eurostar trains added to an already difficult situation for people travelling to and from Britain, where snow fell Sunday across northern England and western Scotland.

Ferries between France and Britain have also been heavily disrupted by the adverse weather conditions, although the port of Calais in northern France was operating normally on Sunday.

Manchester Airport in northwest England was closed on Sunday because of severe weather conditions, while airports in London reported some cancellations and delays.

AFP/Guy Jackson/Expatica