Matt Hancock has announced more parts of the country will be put in stricter tiers in a bid to limit the spread of Covid-19.
The Health Secretary announced the new measures amid rising concerns over the new mutant strain which is thought to have emerged from Kent, as well as new evidence of a new Covid variant which emerged from South Africa.
Here's what you can and can't do under tier 4 restrictions.
Do I live in a Tier 4 area?
More areas of the east and south east of England have been moved into the highest tier, Matt Hancock has announced.
Previously all of London's 32 boroughs and the City of London, and parts of east and south east England, which were previously in Tier 3 moved into the new Tier 4.
However from 00:01 on Boxing Day more areas will be living under the strictest measures.
Those parts of Essex not yet in Tier 4
Waverley in Surrey and Hampshire – including Portsmouth and Southampton but with the exception of the New Forest.
A full list of which area is in which tier is available here.
In a nutshell, what does being in Tier 4 mean?
You must stay at home and only leave for a specific purpose or if you have a “reasonable excuse”.
This includes going to work if it cannot be done from home, shopping for essentials such as food and medicine, attending education or training, using registered childcare, outdoor exercise and for medical reasons.
Who am I allowed to meet up with?
The rules are strict: you cannot meet other people indoors unless you live with them or they are part of your existing support bubble.
Outdoors, you can only meet one person from another household in a public place.
Are support and childcare bubbles still allowed?
Yes, these can continue in Tier 4 areas.
Early years settings and childminders can remain open as normal, while nannies are also allowed to carry on providing services, including in the home.
Do the Tier 4 restrictions apply over Christmas too?
The limitations on meeting people will still apply over the festive period in Tier 4, meaning you will not be able to join or form Christmas bubbles.
Why is this happening now?
The Government has tightened the rules after experts identified a new mutant strain of coronavirus – known as VUI2020/01 – was spreading more quickly in the new Tier 4 areas.
Mr Johnson said the strain may be up to 70% more transmissible than the old variant and could drive up the reproductive rate of the virus.
There are also concerns about another mutant strain which is thought to have emerged from South Africa.
Can I still do some last minute Christmas shopping?
Your options are going to be limited.
In Tier 4 non-essential retail must close, including clothing and homeware stores, betting shops, tailors, tobacco and vape shops, electronic goods and mobile phone shops.
However, these stores can continue to operate click-and-collect systems, if goods are pre-ordered and collected off the premises, and delivery services.
“Essential” retailers such as food shops, supermarkets, pharmacies, garden centres, off-licences and Christmas tree retailers can continue to open.
What do I do if I’ve already made Christmas plans?
England’s chief medical officer Professor Chris Whitty put it bluntly when he said people considering leaving Tier 4 areas now should unpack their bag and stay at home.
He urged people not to risk spreading the new coronavirus variant to an area with low prevalence of the strain.
Can I still get out for some exercise?
Yes. You are allowed to take unlimited exercise alone, or in a public outdoor place with your household, support bubble, or one other person.
Indoor leisure and sports facilities, including gyms, must close in tier 4.
But I’m not able to leave a Tier 4 area?
Within a Tier 4 area people can only leave home for work, education or the limited number of other legally permitted reasons.
Residents are encouraged to keep their travel local, reduce their number of journeys and avoid leaving their village, town or city area.
Walking and cycling is also recommended, with people advised to avoid public transport at busy times.
You should not leave a Tier 4 area unless for permitted reasons, such as work, education, caring responsibilities, to visit a support bubble or for medical reasons, and someone from a Tier 1, 2 or 3 area should not enter a Tier 4 zone except for the same reasons.
Are pubs and restaurants staying shut then?
The pandemic nightmare continues for the hospitality sector, with cafes, restaurants, pubs, bars and social clubs having to stay closed under Tier 4.
They can, however, provide food and drink through takeaways until 11pm, click-and-collect, drive-through or delivery.
Elsewhere, entertainment venues such as theatres, concert halls, cinemas, museums, galleries and casinos also must shut their doors.
Can I get a haircut?
The lockdown long-haired look is set to return, with personal care venues such as hair, beauty, tanning and nail salons closed in Tier 4.
What about schools?
The Government said schools and colleges will remain open during term-time in Tier 4 areas, arguing that it is important for children and young people’s education and well-being to attend.
All secondary schools and colleges in England will be offered help to roll out free coronavirus testing from the first week of January.
Can I visit an elderly relative at a care home?
Visits to care homes are allowed if arrangements are in place to protect residents via screens, visiting pods or behind windows.
However, the Government said “close-contact indoor visits supported by testing” are not allowed in Tier 4. Updated guidance is due to be issued.
Can I go to church over the festive period?
Communal worship is permitted in Tier 4, but people should not mingle with anyone outside their household or bubble.
Funerals up to a maximum of 30 people can go ahead.
Weddings and civil partnership ceremonies should only take place in exceptional circumstances – such as a “deathbed wedding” – with these limited to six people.
Can I still escape for a Christmas holiday?
No. Government guidance states you cannot leave home for holidays in the UK and abroad, nor stay overnight away from your main home unless legally permitted.
This includes staying at a second home, caravan or with someone outside your household or support bubble.
You can only stay overnight away from home for specific reasons, such as for work purposes, while moving house, attending a funeral or you have no fixed address.
I’m already on holiday in a Tier 4 area, what should I do?
The guidance says you should return to your home “as soon as practical”.
Hotels, hostels, guest houses and campsites must close in Tier 4 except if they act as someone’s main residence, where the person cannot return home, for homeless people, or where it is essential to stay there for work purposes.