Snow and ice warnings cover much of Scotland and northern and south-west England, as well as parts of Wales and Northern Ireland, as a cold snap prompts fears of a winter energy crisis. Ministers said on Thursday they were taking advice on how to protect vulnerable people from the cold after research suggested millions of households could not afford to heat their homes. Schools in Scotland were closed or delayed opening their doors as the first snow of the winter fell. Forecasters issued yellow warnings that stretched into the weekend, after the UK Health Security Agency (UKHSA) issued a level 3 cold weather alert covering England from Wednesday evening through to Monday. In the Commons on Thursday, the Cabinet Office minister, Oliver Dowden, was asked to set out how he planned to help the most vulnerable. Afzal Khan, who is shadow justice minister but was speaking from the backbenches, said: “The UK’s power supply is already stretched to breaking point, with the National Grid telling us that blackouts are now a very real possibility. “Can the minister urgently explain to my vulnerable constituents what they should do to remain safe and warm in the event of a power blackout during freezing cold temperatures?” Dowden said: “In respect of the winter weather, the Cabinet Office is keeping a close eye on it, and indeed I have been briefed on the situation. On the wider situation in relation to energy supply, I am working closely with my colleague [the business secretary Grant Shapps]. “He and I have strong confidence about the resilience of the UK power networks. And excepting a very exceptional circumstance, we are confident that we will continue supply throughout the winter.” Earlier on Thursday, research from the Joseph Rowntree Foundation suggested many households would struggle to pay for warm clothing, heating and food, while more than 700,000 were unable to afford essentials and were already in arrears. The UK is facing further low temperatures, as forecasters predict that “showers will turn more wintry with an increasing risk of snow as the week progresses, particularly in coastal areas or over higher ground”. The Met Office said: “There will be widespread frosts with temperatures falling to as low as -10C overnight in isolated spots by the end of the week.” It warned of ice in coastal and northern England, with snow and ice expected in northern Scotland. Motorists were warned of treacherous conditions on roads and railways were also likely to be affected, with longer journey times, forecasters said. Icy conditions may result in some slips and falls and there may be icy patches on untreated roads, pavements and cycle paths, the Met Office said. The RAC urged people to keep blankets in their vehicles in case they break down in icy conditions. The charity Age UK advised people to maintain a supply of food and medicine to reduce the number of outdoor trips, and torches with spare batteries in case of a power cut.