More than three-quarters of England’s population will enter 2021 being urged to “stay at home”, with the reopening of schools also delayed in the hardest-hit areas, as the government battles to contain the new variant of coronavirus. Boris Johnson warned the public it was time to “redouble our efforts” against the virus on Wednesday, as the government used a one-day sitting in the House of Commons to announce a slew of tough new measures, including plunging many more areas into tier 4. Amid criticism of the government’s fractured approach to the start of the new school term and renewed calls for a national lockdown, the prime minister said: “No one regrets these measures more bitterly than I do. But we must take firm action now.” It came as the UK reported another 981 Covid-related deaths, the highest daily toll since April, and a further 50,023 infections in the last 24 hours, amid ongoing fears that the NHS risks being overwhelmed in the worst affected areas. The large increase in deaths may in part be due to a lag in reporting over the Christmas period. At a Downing Street press briefing, the government’s deputy chief medical adviser, Jonathan Van-Tam, struck a sombre note – and stressed that the impact of the extra infections that would result from Christmas mixing had not yet been felt. “Unfortunately it is a pretty grim and depressing picture at the moment. The situation in the UK is precarious in many parts of the country,” he said. The health secretary, Matt Hancock, announced a dramatic tightening of restrictions, with another 21 million people entering tier 4 – under which the public are urged to stay at home and non-essential retail and close-contact services such as hairdressers are shut down. Tier 4 was only introduced 10 days ago, as the government hastily curtailed plans for five-day “Christmas bubbles” with just days to go. It initially covered London and the south-east, where the new variant of the virus first emerged. But Hancock announced on Wednesday that all of the north-east of England, Greater Manchester, large parts of the Midlands and the south-west would be moved into the strictest tier 4 rules from Thursday morning. This “stay at home” zone will now cover 78% of England’s population – and a string of other areas will be moved up from tier 2 to 3. All of mainland Scotland, Wales and Northern Ireland are already subject to the tightest restrictions. Many local leaders were taken by surprise on Wednesday by the scale of the shift. Leaders in north-east England called for a national lockdown to curb the spread of the disease and focused efforts on the rollout of two vaccines. “This is a national problem and a national solution is required now,” they said. Johnson conceded that the government had discussed the option of a national lockdown, but rejected it. “That obviously was an option that we considered intensively,” he said, but given uncertainties about how effective tier 4 measures will be in controlling the new variant, “we thought it right to continue with the tiering,” he said. But he added: “We’re going to keep reviewing this, for all parts of the country.” Hancock was immediately followed in the House of Commons by the education secretary, Gavin Williamson, who announced that secondary schools across England would be closed to almost all pupils for the first two weeks of term. Children of key workers and vulnerable children will be allowed to attend and those in exam years 11 and 13 will return after one week. Williamson also said primary schools would remain shut to most pupils – initially for an extra fortnight – in some areas, but was unable to specify which they would be, leaving baffled parents searching the government website for clarification. The Department for Education later published a list of the affected areas, which include most London boroughs and substantial parts of Essex and Kent. This patchwork approach to reopening schools followed a tussle between cabinet ministers including Williamson, who wanted to keep schools open, and others including Hancock and the Cabinet Office minister, Michael Gove, who wanted to be more cautious. Williamson stressed that the “vast majority” of primary schools would reopen as planned on 4 January. The mayor of London, Sadiq Khan, questioned why some London boroughs were being told to reopen primary schools, and others to keep them closed. “It will be very confusing for parents that some primary schools will be open, and others down the road won’t,” he said. The number of Covid patients in English hospitals surpassed the first-wave peak on Sunday, with 23,771 people in hospital with the disease on Wednesday and numbers expected to rise further as cases climb. On Tuesday, cases reached a record high, with 53,135 reported in the UK. The Covid variant discovered earlier this month accounted for a majority of all new cases in London, the south-east and east of England, Hancock said on Wednesday. Areas moved into tier 4 include all of the Midlands except Worcestershire, Herefordshire, Shropshire, Telford and Wrekin, and Rutland, which will all be in tier 3. In the north-west, Greater Manchester, Lancashire, Blackpool and Blackburn with Darwen, Cheshire, Warrington and Cumbria will be in tier 4. Liverpool will be moved up to tier 3. In the south-west, Gloucestershire, Swindon, Somerset, Bournemouth, Christchurch and Poole will be in tier 4, while the remainder of the region – including Cornwall, Devon and Dorset – will be moved up to tier 3. Hancock told the Commons that Wednesday was “a day of mixed emotions” due to the announcement of the new restrictions hours after the Oxford/AstraZeneca vaccine was approved by the UK’s medical regulator. He told MPs: “It brings forward the day on which we can lift the restrictions that no one in this house wants to see any longer than are absolutely necessary. But we must act to suppress the virus now, not least because the new variant makes the time between now and then even more difficult. “And so whilst we have the good news of the vaccine today, we also have to take some difficult decisions.” Hancock said he knew the measures would place a significant burden on businesses and livelihoods but that it was “absolutely necessary because of the number of cases that we have seen”. Andy Street, the Conservative mayor of the West Midlands, said the tier 3 rules had been unable to halt an increase in cases across the region. He said he would continue to press the Treasury for more financial support for businesses, adding: “I will continue to make the case vociferously to government, and will not relent until we achieve a breakthrough.”