The Christmas travel plans of thousands of passengers are in disarray after snow left Heathrow Airport all but shut.
Thousands have been forced to sleep overnight in airports and there is disruption to road and rail travel with the Met Office warning of more snow on the way.
Temperatures struggled to get above -5C (23F) overnight and BBC forecaster Matt Taylor said there were lows of -19C (-2F) in parts of Worcestershire and Shropshire.
"Heathrow Airport will not be accepting arrivals on Sunday, and will only manage a handful of departures as our airfield team continues to deal with the impacts of yesterday's bad weather and prepares the airport for a full re-opening on Monday.
"No flights will operate from Terminals 1 or 4 and a limited number of departures will leave from Terminals 3 and 5. We are extremely sorry for the disruption this will cause to passengers and airlines and we stress that passengers must check with their airlines before travelling to the airport. We will provide regular updates and you can contact your airline here.
"This morning, we listened carefully to the advice of our airside operations team and reluctantly judged that while Heathrow's northern runway remains clear, the change in temperature overnight led to a significant build up of ice on parking stands around the planes and this requires the airfield to remain closed until it is safe to move planes around.
"We have 200 aircraft parking stands and have a team of several hundred people working to treat these airside areas and to keep passengers in the terminal as warm and as comfortable as possible while we do everything we can to get Heathrow moving.
"We are removing 30 tonnes of snow from each stand, but the temperature remains firmly below zero and Heathrow's capacity is limited to the extent that all parking stands are occupied by aircraft, making the job of clearing and treating them more difficult.
"Safety is our first priority and we hope this course of action will allow us to offer a fuller service to passengers and airlines using Heathrow tomorrow."
"We are aiming to get seven departures away from Heathrow today. At Gatwick we will be flying as many as possible but it will be a reduced operation because yesterday has had an impact and many aircraft and crew are in the wrong place.
"We had to divert flights (from the Far East) to Athens and Spain because Heathrow was closed. There are no arrivals at Heathrow today so they will have to stay where they are but we are looking after all our passengers (in hotels etc). The advice is not to leave home without checking the BA website. Don't go to the airport unless your flight is confirmed.
"We are in the hands of the weather. We are doing all that we can for our customers within the restrictions that the airports are functioning under."
"All BMI flights into and out of Heathrow have been cancelled and will not resume until probably 10am tomorrow. A lot depends on how quickly Heathrow can resume flights. It's one of those unfortunate situations.
"Like all the other airlines we will run flights as soon as we can and will try to find room for those whose flights have been cancelled. It's one of the busiest weeks of the year and we need to get Heathrow up and running. Sometimes the weather is not as bad as it's forecast but if the weather gets worse later in the week then it could get quite nasty.
"The advice is not to go to Heathrow today. If you have flights tomorrow or later in the week keep checking our website and turn up for your flight unless you hear otherwise."
Transport Secretary Philip Hammond
"The strategic road network is open and, by and large, it has remained open and passable with care. Given the very severe conditions the Highways Agency and local authorities have worked well to get the roads open.
"The real problems have been in the air. I understand the immense frustration of people, many of whom will be with families looking to get away for Christmas. The airports operators and the airlines have a difficult balancing act to perform here. They have to think about getting services back to normal operation as quickly as they possibly can.
"In Russia and Scandinavia they are used to these conditions and they have far more investment in equipment to deal with them. Now we could do that too. We could spend hundreds of millions, or billions of pounds on additional winter resilience equipment but if we spend it on that we won't be able to spend it on something else and that's a decision we as a society need to make.
"And I have asked the government's chief scientist to give us a report on future weather assumptions - whether we should simply assume for future winters that we are going to experience multiple bouts of extreme weather and if is answer is 'yes, that should be our assumption' then we will have to sit down collectively and decide how to reprioritise our investment in the transport infrastructure to focus it towards winter resilience."
Shadow chancellor Alan Johnson
"It is a big issue when people believe the government have just left it for them and said 'get a shovel or stay at home'. Governing is about more than that when you hit a crisis.
"We commissioned this report by David Quarmby, chair of the RAC, and no-one has heard anything of it. That was specifically to look at the points that Philip Hammond [transport secretary) is now saying we should look at again. He already has a report and nothing has emerged on that.
"Secondly the salt supplies, they were supposed to be delivered in time, this is this government's responsibility, not the previous government and we hear they are going to be coming in dribs and drabs right into next year. They should have been here now.
"This is one of the big worries for government, what this does in terms of the economy because if people are not getting out to the shops, there is not the demand in the shops then obviously that has an effect.
Foreign Secretary William Hague
"We have got higher salt stocks than at this time last year; we have got higher gas reserves than at this time last year.
"So I think there was a heavy snowfall of political opportunism really in his [Mr Johnson's] comments.
"As my colleague the Transport Secretary has said, we have not been equipped over the last few decades in this country to cope with every aspect of severe, prolonged cold weather. We may have to look again at that if these things are to recur frequently."