To "simplify" the rules, Boris Johnson has ushered in a new model of “Local Covid Alert Levels” in England which will work as a traffic light system.
It will see different parts of the country placed into different categories based on the rates of infections.
In areas with particularly high levels of infection pubs, gyms and casinos could be forced to closed in order to stop the spread.
The Prime Minister said the new Covid alert levels were being introduced to "squash this virus wherever it appears".
"We are today simplifying, standardising and in some places toughening local rules in England by introducing three levels of Covid alert," he told the Downing Street briefing.
He assured: "Nowhere will be shut down indefinitely."
And he added "no one affected by this will be left to fend for themselves", with the Government having previously announced new financial assistance.
"No one least of all me wants to impose these kinds of restrictions, erosions of our personal liberty, but I'm convinced as I've ever been that the British people have the resolve to beat this virus and that together we will do just that," Mr Johnson said.
Why is this changing?
The Government recognises that local lockdown rules have become complicated and difficult to enforce so is attempting to simplify the system with the “rule of three”.
Under the system there will be three tiers - medium, high and very high.
Use our interactive tool to see which tier your area falls under in England's new system for local lockdowns.
Medium level/tier one
The medium level covers most of the country and consists of the current national measures. This means those in a tier one area must abide by the “Rule of Six” and the closure of venues at 10pm.
All businesses and venues can continue to operate, in a Covid-secure manner, other than those that remain closed in law, such as nightclubs and adult entertainment venues.
Certain businesses selling food or drink on their premises are required to close between 10pm and 5am. Businesses and venues selling food for consumption off the premises can continue to do so after 10pm as long as this is through delivery service, click-and-collect or drive-thru.
Schools, universities and places of worship remain open
Weddings and funerals can go ahead with restrictions on the number of attendees
Organised indoor sport and exercise classes can continue to take place, provided the Rule of Six is followed
People must not meet in groups larger than six, indoors or outdoors
High level/tier two
This is for areas with a higher level of infections. This means the following additional measures are in place:
People must not meet with anybody outside their household or support bubble in any indoor setting, whether at home or in a public place
The "Rule of Six" will continue to apply outdoors and in private gardens.
People should aim to reduce the number of journeys they make where possible. If they need to travel, they should walk or cycle where possible, or to plan ahead and avoid busy times and routes on public transport.
Very high level/tier three
This is for areas with a very high level of infections. The Government will set a baseline of measures for any area in this local alert level. Consultation with local authorities will determine additional measures.
The baseline means the below additional measures are in place:
Pubs and bars must close, and can only remain open where they operate as if they were a restaurant - which means serving substantial meals, like a main lunchtime or evening meal. They may only serve alcohol as part of such a meal.
Wedding receptions are not allowed
People must not meet with anybody outside their household or support bubble in any indoor or outdoor setting, whether at home or in a public space. The Rule of Six applies in open public spaces like parks and beaches.
People should try to avoid travelling outside the ‘Very High’ area they are in, or entering a ‘Very High’ area, other than for things like work, education, accessing youth services, to meet caring responsibilities or if they are in transit.
People should avoid staying overnight in another part of the UK if they are resident in a ‘Very High’ area, or avoid staying overnight in a ‘Very High’ area if they are resident elsewhere.
But measures could go further...
The Government will discuss bringing in further measures for tier three, which could include the closure of parts of the entertainment sector or tourist attractions such as casinos or betting shops.
When will this come into force?
The measures are expected to come into effect on Wednesday and will be debated and voted on in Parliament.
Where is affected?
The Liverpool City region has been subjected to tier-three restrictions which affects Liverpool, Knowsley, Wirral, St Helens, Sefton and Halton. However there is still disagreement about a financial support package for the area now that harsh measures have been imposed.
A statement from seven local leaders, including Metro mayor Steve Rotheram and Liverpool Mayor Joe Anderson said: "We made it clear we do not feel that the furlough scheme announced recently is adequate and that businesses in the region especially those in the hospitality sector and those serving it will be damaged and many will suffer long-term damage or close for good.”
Meanwhile, Manchester will be placed into tier-two restrictions.