Prime Minister David Cameron has said he is “frustrated” by the continued disruption at Heathrow as the Government offered military support to help clear the snow.
While thousands of air passengers remain stranded, rail travellers have also been hit by widespread disruptions and hundreds of people had to be evacuated from stricken trains.
The East Coast line, one of the country’s main railway arteries, was suspended between London and Peterborough with passengers advised to stay at home after faults on the overhead power cables.
And with Christmas being the busiest travel period of the year, the AA is preparing for increasing problems on the roads – and it is already dealing with 2,000 breakdowns an hour.
Speaking at a Downing Street news conference, Mr Cameron said: “If it’s understandable that Heathrow had to close briefly, I’m frustrated on behalf of all those affected that it’s taking so long for the situation to improve.
“There have been intensive discussions between (Transport Secretary) Philip Hammond and BAA about how best to ensure that normal flying capacity is resumed as soon as possible.”
Heathrow said it will operate about a third of scheduled flights until at least 6am on Thursday.
BAA chief executive Colin Matthews and BAA chairman Sir Nigel Rudd met Mr Hammond at Heathrow. The minister said: “What we’re trying to do now is focus our entire energy on providing BAA with the maximum support to get as many passengers away as possible before the holiday weekend.
“We’ve offered BAA the use of troops if they need additional manpower for snow clearing although they tell us they’ve actually got the manpower they need here.”
Eurostar is operating a reduced service and passengers have again been queuing for hours in an attempt to get on the services which are running. Speed restrictions are in place on its high-speed lines, adding up to two hours to journey times.