Britain’s prime minister Boris Johnson imposed a new lockdown on England on Monday night in an effort to stop hospitals from being swamped by a surge in coronavirus cases driven by a new variant.
Schools will close, all non-essential shops will be shut and citizens will be urged to stay at home.
Johnson outlined the tougher restrictions in a televised address even though Britain boasts Europe’s most expansive vaccination programme with more than one million injections administered.
"But I really do believe we are entering the last phase of the struggle because with every jab that goes into our arms we are tilting the odds against Covid and in favour of the British people," he said.
"Thanks to the miracle of science, not only is the end in sight but we know exactly how we are going to get there."
Wales, Northern Ireland and Scotland announced similar measures on Monday night as chief medical officers in each region increased the Covid alert level from four to five for the first time.
The new lockdown is expected to last until the middle of February and will come into effect after MPs consider the implications on Wednesday.
Under the order, schools and colleges will move to remote learning except for vulnerable children and the children of key workers. University students will be expected to study from their lodgings until at least mid-February.
Restaurants will be allowed to continue deliveries or take-aways but outdoor sports venues including gyms, tennis courts and golf courses will close.
Elite sport, including Premier League football matches, will be played.
Johnson said the weeks ahead would be hard in a country where more than 75,000 people have died from the coronavirus since January 2020.
He added: "But if our understanding of the virus doesn’t change dramatically once again, if the rollout of the vaccine programme continues to be successful, if deaths start to fall as the vaccine takes effect, then I hope we can steadily move out of lockdown and cautiously, to move regions down the tiers."