Heavy snow on the busiest changeover day of the ski season caused disruption that left hundreds of Brits sleeping in cars and on the floors of schools and gyms.

Roads were closed amid car crashes as half a metre of snow fell on resorts in the French Alps in less than 24 hours on Friday night and Saturday, leaving 4,000 tourists stranded, The Times reported.

The Red Cross was called to provide food and water at Chambery airport, where more than 500 holidaymakers slept on the floor after their flights were cancelled and transfer coaches, stuck in the gridlock, failed to arrive.

The French Alps saw 35 inches of snow fall on December 30, according to weathertoski.co.uk.

The Times said the N90 dual carriageway between Albertville and Moûtiers, which serves the Three Valleys ski area and the resorts of Tignes, Val-d’Isère and La Plagne, was one of the worst-affected routes and that authorities opened emergency shelters and a “crisis centre” in Albertville.

British tourists criticised holiday companies. Neil Hartley tweeted: “Weather may have caused the problems, but failure to act early enough, incompetence and outright lies have made things much worse.”

The Daily Mail said popstar Pixie Lott was among the stranded holidaymakers and spoke to mother-of-two Claire Nicholas, who said it took her more than 48 hours to get from Les Arcs back home to Chippenham in Wiltshire – including an eight-hour bus trip.

She said: “It was absolutely outrageous. The reps were way out of their depth. They didn’t know how to handle the situation.”

Ruby Hodges, a British student who was travelling to La Plagne, told the Times: “It was absolute chaos.

“We were stuck in gridlock for three hours and moved only 300 metres. When we reached Moûtiers, the ski company rep said we needed to turn back to Albertville for the night.

“When we arrived, we were put in a hall with 250 other people and there was no water or food.”

Weather forecaster Meteo France issued an amber alert for snow and ice in the Savoy and Haute Savoy departments. Bison Futé, the French highways monitor, classified roads in the region as orange, its second highest level of concern.

After the incident, France’s interior minister ordered an investigation into why emergency plans had not stopped so many vehicles becoming stranded.