British Airways says it has cancelled 2,000 flights and diverted 40 fully-laden planes to other airports around the UK and Europe over the past six days, one of its busiest periods of the year.
It hopes to operate a full long-haul departure schedule from Heathrow on Thursday and Christmas Eve and is using larger planes than usual on short-haul routes to accommodate more passengers.
Cross-Channel operator Eurostar said it planned to run 43 out of 52 services from London St Pancras on Wednesday, having restored normal check-in procedures.
It advised passengers to turn up only if they had a valid ticket, and only an hour before they travelled.
On Wednesday morning, some passengers were reporting empty seats on Eurostar trains out of London, despite people being left on platforms amid continuing chaotic scenes and long queues.
Asked about the country’s travel problems, the prime minister said: “I completely understand and share people’s frustrations when you can’t get home, can’t get to work, can’t see loved ones and Christmas travel plans are sent awry.”
But Mr Cameron insisted the government was “on top of the situation”, having relaxed rules on night flights at airports and allowed lorry drivers to work longer hours.
The country had enough road salt and a good stock in reserve, he said, but added that priority had to be given to the strategic road network or motorways, A-roads and dual carriageways over treacherous side roads and pavements.
After suspending services because of damage to overhead power lines on Tuesday, Elaine Holt, the chairwoman of train operator East Coast, said: “Network Rail are going to look very closely at their infrastructure and what they can learn from this.”
Rail watchdog Passenger Focus said the recent bout of cold weather should act as a wake-up call for the industry to provide better information.
Chief executive Anthony Smith said: “What we’ve seen recently is lots of cases where we’ve had websites saying different things, we’ve had phone lines saying different things and we’ve had staff saying different things as well.”