Millions of people in England will find themselves moved to the country's tightest level of restrictions on December 26, known as Boxing Day in the UK, as the government grapples to contain the “dangerous” spread of the new COVID variant.
The "stay at home" order also includes the closure of non-essential shops and strict one-on-one meeting limits outside between households.
Health Secretary Matt Hancock also revealed that two cases of another new variant of COVID-19, linked to South Africa, have been identified in the UK.
"This new variant is highly concerning, because it is yet more transmissible, and it appears to have mutated further than the new variant that has been discovered in the UK," he said.
"We've taken the following action: first, we are quarantining cases and close contacts of cases found here in the UK. Second, we're placing immediate restrictions on travel from South Africa."
New variant identified in European countries outside the UK
Meanwhile, the UK-discovered new variant of the virus spreading rapidly in England's south-east has also been confirmed in Denmark, Italy, Gibraltar, the Netherlands and Australia.
French health minister Olivier Véran said it is "entirely possible" the new variant is already circulating in France, but no cases have been officially identified yet.
An expert in the UK said on Wednesday that it is likely already in most European countries given that the UK does more genome sequencing that others.
Parts of southern England are now in a full "Tier 4" lockdown with non-essential shops closed, and more areas will lockdown from December 26 as cases rise rapidly.
In the week from 12 to 18 December, an estimated one in 85 people were suspected of having coronavirus, the UK's Office for National Statistics (ONS) said, adding that the number of people testing positive has continued to increase.
They estimate that around one in 60 people in Wales had coronavirus over the same period.
"London, the South East, and the East of England have the highest percentages of positive cases that are compatible with the new variant of the virus," ONS said.
Italy logs highest death toll in Europe
Italy is ending the year with an unenviable death tally reaching over 70,000, becoming the fifth nation in the world to surpass this mark.
With an updated total of 70,395 fatalities from the virus, it has the highest in Europe.
The country is beginning a nationwide lockdown as the government tries to curb a rise in coronavirus infections that could be triggered by the festivities.
Europe poised to vaccinate citizens
Authorities are getting ready to begin a mass vaccination programme across EU countries.
Pfizer and BioNTech have readied 12.5 million doses as European countries get set to start vaccinating the most vulnerable. Several EU countries will begin in a few days, others will follow in the New Year.