The Conservatives have claimed that the government's call for less salt to be used to grit roads during the prolonged cold snap is an "admission of failure".
Transport minister Sadiq Khan came to the Commons this afternoon to answer questions from MPs about the severe weather and its impact on transport services.
He said the cold weather is "likely to continue for some days longer" and he thanked the thousands of people working to keep major roads, ports, airports and train lines open.
The UK is experiencing its most prolonged period of cold weather since 1981.
Khan said the "key priority" of the Department for Transport is to keep national and local "core transport networks" operational.
The Highways Agency is using its 500 grit spreaders and snow ploughs on the major routes under their control, while local authorities are responsible for other roads.
Last week the Salt Cell group met – it directs suppliers to deliver to the areas most in need of supplies of salt.
The Local Government Association (LGA), the Highways Agency, the cabinet office, the transport department and the devolved assemblies sit on the group, which will meet again tomorrow.
Further measures may be required this week "to get salt where it is needed".
The Highways Agency has reduced its salt use by 25 per cent and the LGA and Mayor of London have agreed to similar actions, but local authorities will make their own decisions.
Khan said there is no shortage of gas and winter fuel and cold weather payments are being paid. He said there have been no reported problems with food supply.
The minister said that with forecasts of a further period of snow and sub-zero temperatures, the country should continue to "pull together for the common good".
Shadow transport secretary Theresa Villiers said many communities have had "three solid weeks" of treacherous conditions and said there are "important questions" to answer about the government's preparations.
She said it was "not acceptable to pass the buck to local authorities" over "shortages" of salt.
Villiers asked for an estimate of the cost of repairs to the roads, which are damaged by the use of grit.
She raised press reports that people and businesses that clear public paths could be open to litigation.
Villiers told MPs that elderly people are at risk because many pavements and minor roads have not been gritted and some councils have found it impossible to get more salt.
Khan accused his Conservative shadow of "mean spiritedness" and said he would not "point fingers" at Tory-run councils who are not coping with the weather conditions.
"Either we are a nanny state or we trust councillors," he said.
He said the 25 per cent reduction in salt use was only a proposal and he cannot force local authorities to do so.
Khan condemned "scare-mongering" about people being sued for clearing pathways and said press reports had added to the confusion.
He reiterated that the country is suffering the most prolonged spell of cold weather for 29 years and said councils would be criticised for building up large supplies of salt and then not using it.
Lib Dem transport spokesman Norman Baker told the House that if the weather deteriorated the country could run out of salt.
He said some councils are not gritting enough and using the lack of salt as an excuse.
Baker asked for an estimate of the long-term costs of road repair.
Khan said councils would have to look at the costs of storing salt for longer and investing in salt bins, given that they in fact infrequently grit roads.
"I cannot give advice centrally about where to grit," he added.
Anne Main (Con, St Albans) and Greg Barker (Con, Bexhill and Battle) both complained about serious disruption to train services in their constituency.
Barker said it was unacceptable that station platforms have not been cleared of snow and ice.
Natascha Engel (Lab, Derbyshire NE) said roads in her rural constituency are a "lifeline," while John Redwood (Con, Wokingham) said schools should find alternative teaching days to replace those lost because of the weather.
Bob Russell (Lib Dem, Colchester) said: "When I was a lad, schools did not shut because of snow".
He asked the minister to dispel the "urban myth" that people could be sued for clearing pathways and pavements.
Khan said that while there probably is a case where someone was sued, the public should not be "frightened" to do so.
Andrew Selous (Con, SW Bedfordshire) said that lessons should be learnt about salt supplies from the UK being exported and called for "British grit for British roads".
Nigel Evans (Con, Ribble Valley) said that farmers who wanted to help clear rural routes but they have been told they need an NVQ in health and safety before they can do so.
Khan said that was news to him and deplored that "people who can help are being deprived of doing so".
