Thousands of air passengers were left stranded last night as scores of pre-Christmas flights had to be cancelled because of thick fog.

Conditions prevented planes from taking off from Gatwick and Southampton airports while incoming flights had to be diverted away from both Stansted and City.

The disruption came as airports across the country prepared for one of the busiest weekends of the year, with a rush of people attempting to fly home for Christmas.

Gatwick was one of the worst-hit, with as many as 2,000 people affected by cancellations. Around 16 departures were cancelled at the airport last night, 12 of them Easyjet flights.

At Southampton, hundreds of passengers were left stranded with all flights in and out cancelled.

The fog hit motorists too. They faced delays caused by accidents, tail-backs and freezing conditions last night with the prospect of more fog and ice as the holiday getaway continues.

The Met Office gave warning of a “sharp frost” over the South East and East Anglia by this morning as millions more people take to the roads.

A spokesman for the Met Office said: “Northern England and Scotland has the biggest potential for travel problems. There is a risk of ice, mostly over Scotland, with snow over mountains in Grampian. That risk continues through the higher ground in northern England, places such as Lancashire, North Yorkshire, Cumbria, Northumberland and Durham.

“Those icy conditions will last during Saturday morning and could cause problems for Scottish airports in Glasgow, Aberdeen and Edinburgh.”

The National Traffic Control Centre said that patchy fog was also likely, with freezing rain, in the west of the country stretching from Birmingham to the Scottish borders.

An estimated four million people used the railways yesterday, the last day of regular services before the holidays. The biggest disruption over the holidays will probably be the closure of the West Coast main line, which connects London, the North West and Scotland, from December 27 to 31 because of engineering works.

About 3.5 million Britons are to leave the country over the holidays, with 1.2 million to pass through Heathrow. Eurostar expected 150,000 people to travel from its new terminal at St Pancras.

About 250 people face Christmas without jobs and hundreds of holidays have been cancelled after a travel company went into administration. Travelscope Holidays, of Brockworth, Gloustershire, collapsed after two “disastrous” cruises — one hit by a vomiting virus, the other by the death of a passenger — caused financial problems and cancelled bookings. All bookings will be refunded.