An Air Malta flight to Heathrow this afternoon has been delayed as one of airport's two runways had to be closed for de-icing and snow clearance.

The flight, scheduled to arrive in Heathrow at 4.50pm, is now estimated to arrive at 7.10pm.

Travellers were engulfed in snow all over the UK today, with roads shut, trains cancelled or delayed and flights disrupted.

Millions who had decided conditions were not so bad after all were already at work when the first flurries hit the London area.

Driven by strong winds, the snow settled quickly and travellers who had had trouble getting on to reduced-service trains in the morning were wondering how they were going to get home tonight.

As the snow spread, so did the travel chaos. Earlier, Wales, the West Country, eastern England, the North East of England and Scotland had been the worst-hit areas.

But soon the whole country was in winter's grip, with flights cancelled at Heathrow airport and snow reaching London.

The northern runway at Heathrow was shut at about 10.20am for de-icing and snow clearing.

A Heathrow spokesman said the work, which was expected to take around 45 minutes, meant there were delays and cancellations at the west London airport.

He added that it was possible that the southern runway might have to be closed for similar work to be done once the northern one was reopened.

At least 70 flights were cancelled at Heathrow. British Airways said it had axed 60 flights. Airports where flights were cancelled included Southampton, Bristol, Glasgow, Jersey and Newcastle.

Some train companies had operated special timetables even before the snow arrived, prompting some passengers to complain of overcrowding.