England will enter its toughest nationwide lockdown since March, with schools closed until mid-February, as Boris Johnson warned that the weeks ahead “will be the hardest yet”. As new figures put the UK on course to exceed 100,000 Covid-related deaths before the end of the month without urgent action, the prime minister said once again that people must stay at home, with exercise limited to once a day. All non-essential shops were told to close from Monday night. The lockdown will last for at least seven weeks, with measures to be reviewed during half-term week. Any relaxation would not come into effect before 22 February. Just a day after urging millions of pupils to return to the classroom, Johnson announced all schools would switch to remote learning until the February half-term, and GCSE and A-level exams were unlikely to go ahead as planned. The prime minister said parents would “reasonably ask why we did not make this decision sooner”, adding: “I completely understand the inconvenience and distress this late change will cause millions of parents and pupils up and down the country.” In an 8pm address to the nation, the prime minister said he hoped that 12.2 million of the most vulnerable in society – care home residents and staff, frontline health and social care workers, all over-70s and the clinically extremely vulnerable – would get their first vaccinations by mid-February. The vaccines minister, Nadhim Zahawi, later said these four groups added up to 13.9 million people in England. The UK was entering “the last phase of the struggle”, Johnson said, adding: “With every jab that goes into our arms, we are tilting the odds against Covid and in favour of the British people.” The crackdown comes amid catastrophic figures for hospital admissions in England and warnings of a grim death toll by the end of the month. Johnson said: On 4 January, there were 26,626 Covid patients in hospital in England, up 30% on a week earlier. The peak of admissions in the first wave was 18,374 on 12 April; the country is now 40% above that level. Across the UK, there were 80,664 positive tests on 29 December, with the case rate three times higher than at the start of December. According to a Guardian analysis, there have been 91,453 deaths in the UK with Covid-19 on the death certificate or within 28 days of a positive test. Given the current trajectory, the UK could reach the grim milestone of 100,000 deaths before the end of the month, experts warned. On Monday, the UK’s chief medical officers recommended that the Covid alert move to its highest level, from 4 to 5, meaning there is a “material risk of healthcare services being overwhelmed” and necessitating extremely strict social distancing. “We are not confident that the NHS can handle a further sustained rise in cases and without further action there is a material risk of the NHS in several areas being overwhelmed over the next 21 days,” the chief medical officers of the four nations said, while urging those who still need emergency care for other illnesses to seek treatment. Other UK leaders also announced new restrictions. All schools in Wales will be closed until at least 18 January, while mainland Scotland will be placed in full lockdown from midnight on Monday for the duration of January. The first minister, Nicola Sturgeon, said it was “no exaggeration to say that I am more concerned about the situation we face now than I have been at any time since March last year”. Northern Ireland also looks set for new curbs, with Arlene Foster, the first minister of Northern Ireland, saying the region faces a “very dire situation”. In his address to the nation, Johnson laid the blame for a third national lockdown squarely on a new, faster-spreading variant of the virus – despite widespread ongoing criticism of the government’s slowness to act. “There is no doubt that in fighting the old variant of the virus, our collective efforts were working and would have continued to work,” Johnson said. “But we now have a new variant of the virus. It has been both frustrating and alarming to see the speed with which the new variant is spreading.” Even in the past 36 hours, the prime minister had insisted schools were safe to open in most areas of the country. “There is no doubt in my mind that schools are safe,” he told the BBC’s Andrew Marr on Sunday. However, the prime minister was unable to identify what he believed had changed since the preceding days, when most schools had been told to remain open – only saying in his address that schools were likely to act “as vectors for transmission, causing the virus to spread between households”. Under the new lockdown, people in England will be ordered to stay at home from Tuesday and advised to leave only once a day for exercise. MPs are expected to vote the tough new measures into law from Wednesday, although businesses were advised to close from Monday night. Across the country, people must now leave home only for work – and only if it is impossible to work from home – and for essential food and medicine. Exercise with one other person from a different household is permitted but the advice is to stay local and limit activity to once a day. Other reasons to leave home will be limited to seeking medical care, fleeing the threat of harm and providing essential care. All primary schools, secondary schools and colleges will be closed apart from for the children of key workers and vulnerable children. “We recognise that this will mean it is not possible or fair for all exams to go ahead this summer as normal,” Johnson said. “The education secretary will work with Ofqual [the regulator] to put in place alternative arrangements.” Nurseries, alternative provision and special schools will remain open and existing rules for childcare support bubbles will continue, but students will not be able to return to university and will be expected to study online from their current residence until mid-February. In-person teaching can take place for a limited number of critical courses, such as medicine. All non-essential retail and hospitality must close or remain closed. Restaurants and other premises can continue to offer deliveries or takeaways, but alcohol will no longer be permitted for takeaway or click and collect amid concerns about people congregating around pubs and bars. Places of worship can remain open and offer communal worship – subject to social distancing – as can playgrounds, but outdoor sports venues, tennis courts and golf courses must close. Outdoor team sports will not be permitted, but professional sports, including the Premier League, may continue. Those who are clinically extremely vulnerable will be advised to shield themselves as much as possible and should not go to work even if they cannot work from home, the government will advise. The lockdown is set to come into effect in law as soon as possible, with regulations to be laid out on Tuesday and voted through parliament on Wednesday – although MPs have been warned not to attend parliament and told to participate remotely. However, Johnson said the new rules should be followed from this evening, and businesses and the public should not wait for regulations to be passed.