Tens of thousands waited in London, Paris and Brussels Monday to hear if they would make it home in time for Christmas after winter snows brought the Eurostar high-speed rail link to a shuddering halt.

French President Nicolas Sarkozy summoned the company's chairman to his offices and ordered him to get the trains back on track by Tuesday after the shutdown that began late Friday and was blamed on "fluffy" snow.

But Eurostar gave no firm promises, saying only that services may partially resume on Tuesday morning if test runs on trains "go well," and that schedules would not get back to normal before Christmas on Friday at the earliest.

Around 75,000 travellers have been left stranded by the cancellation of services on one of the busiest weeks of the year in the run-up to the Christmas break, said Eurostar.

The chaos began when five trains broke down on Friday night amid freezing temperatures and snow in northern France, trapping two thousand passengers overnight in the 50-kilometre (31-mile) tunnel under the English Channel.

Many passengers were outraged at their treatment while trapped on board, with some complaining they had been left for hours without food, drink or information on when and how their ordeal would end.

Transport misery continued on Monday, with travellers in the Eurostar terminals in London and Paris angered that the company cannot yet tell them when they can begin a journey that usually takes just over two hours.

"I come each day intending to be strong, but now, with the fatigue and the lack of information..." 27-year-old British traveller Sze-Wei Lu said as she fought back tears in the Gare du Nord station in Paris.

She was just one of the many thousands waiting to find out if they could get home for Christmas or begin their Christmas holiday trip abroad.

Eurostar, which now faces a giant backlog of passengers, has suspended any further sales until after Christmas.

The winter cold snap that shut down the Eurostar trains has also caused dozens of deaths and major transport disruption across Europe.

Nick Mercer, commercial director of the company jointly owned by the French and Belgian state railway and a private British firm, said Eurostar was still trying to figure out what had gone wrong.

"It was the amount of snow, which was higher than we experienced before, it was lighter than normal, fluffier, and the temperature inside the tunnel and the humidity was higher than normal," he told the BBC.

Eurostar executives said the dry, powdery snow that fell at the weekend was unusual for the north of France and got past screens into the trains' engines.

There it turned into condensation and sparked electrical faults, they said, adding that measures would be put in place to prevent a repeat of the problem.

Meteorologists warned of more snow and ice overnight in the Calais region of France where the Channel tunnel begins.

French and British government ministers expressed outrage Monday over the breakdown and ordered a probe, with British Transport Minister Sadiq Khan saying he was "angry" passengers had still not been told what was going on.

As frustration mounted, Sarkozy summoned Guillaume Pepy, the chairman of Eurostar.

"The president asked that a resumption of traffic be effective by tomorrow, December 22," said a statement issued by his office after their meeting.

Eurostar said it had launched its own review by independent experts into the breakdown of the high-speed trains.

The shuttle service that carries cars and trucks on trains under the Channel was functioning normally Monday, its operator Eurotunnel said, but was taking no more bookings for the moment because it was "saturated".

Eurostar meanwhile said it would compensate the thousands of passengers who had been stuck overnight in the tunnel at the weekend.

They will get double the price they paid for their tickets as well as up to 170 euros (243 dollars) and would have any hotel or taxi expenses reimbursed, it said.

Others who have not been able to travel can exchange their tickets for a later date or have them reimbursed and will have any expenses incurred reimbursed.