LONDON and the south-east have been plunged into Tier 4 coronavirus restrictions - the highest level of England's lockdown system.
From Boxing Day, a raft of other areas in the South and East of England were also plunged into the highest tier, in a bit to control a new mutant Covid strain. But what are the differences between Tier 3 and Tier 4 rules?
⚠️ Read our coronavirus live blog for the latest news & updatesTier 4 restrictions for London and parts of the south east came into force from December 20
Boris Johnson introduced Tier 4 lockdown restrictions for London and the south east on December 19, which came into force the next day.
The Tier is considered to be "very high" with the Government's message being "stay at home".
On December 23, Matt Hancock announced a raft of new areas would be plunged into the toughest restrictions from Boxing Day (December 26).
These areas include Sussex, Oxfordshire, Norfolk, Cambridgeshire, parts of Essex not already in Tier 4, Waverley, and Hampshire.
The restrictions bring Tier 4 areas closer to the rules in force during the national lockdown.
They are different to Tier 3 in many ways, including the following:Large swathes of the South and East of England were plunged into the Tier 4 restrictions on Boxing Day
Stay at home except for work and essential reasons
Just like in full lockdown, Brits in Tier 4 can only leave their homes for essential reasons.
In Tier 3, people are permitted to leave their houses as they choose, providing they follow social distancing when out and about.
All exercise in Tiers 3 and 4 unlimited - unlike in the first lockdown, when it was initially restricted to just an hour a day.
In Tier 4, travel for some reasons - including education, childcare or an emergency - will be allowed.
People in Tier 4 can still go to work - but only as a last resort if they cannot work from home.
In Tier 3, people can leave home and travel to other areas for any medical reason, including to get a Covid test, to be with someone who is giving birth, to escape domestic abuse, or to get treatment for a pet.
But those in Tier 4 won't be allowed to leave their area to travel elsewhere, unless it's for one of the reasons above.
Meeting people indoor and outdoors
Brits living in Tier 4 areas will not be allowed to meet other households inside or stay overnight anywhere else.
The Government says those in these areas must stay in their homes to help combat the spread of the adapted virus.
One person can meet one other person outside in a public place.
But those in Tier 3 are permitted to meet others outside using the Rule of Six.People are ordered to stay at home in Tier 4 except for essential reasons
In Tier 3, all shops including non-essential retail such as clothing, toys and home-ware remain open.
But in Tier 4, all the above must close with only essential businesses open.
Essential businesses include supermarkets, hardware stores, garden centres, banks, post offices, pet shops, petrol stations and pharmacies.
Hairdressers, beauticians and other personal care
Hairdressers, barbers, beauty salons and all entertainment venues are open in Tier 3, providing they operate under Covid safety guidelines.
Gyms are also open in Tier 3 but for individual exercise as classes have been halted.
But in Tier 4, all personal care and venues such as cinemas and gyms have been ordered to shut from December 20.
Pubs, bars and restaurants
The rules for pubs, bars and restaurants remain the same across both Tier 3 and Tier 4.
In both Tiers they can offer delivery or take-out options.
People can also leave to pick up items ordered through click-and-collect services online.