The new measures, set to come in after December 2, amount to a beefed-up version of the original tier system first unveiled in October.
Those restrictions saw different areas of England placed into medium, high and very high alert levels depending on the number of coronavirus cases, with curbs on hospitality, leisure and household mixing implemented accordingly.
Now, as England looks ahead to exiting the national lockdown, how have the tiers changed?
And what about Christmas?
- Will England's lockdown definitely end in December?
Boris Johnson has confirmed that the national lockdown will end on December 2, to be replaced with the new tier system.
- So what do the new tiers mean?
As before, there will be three tiers, with Tier 3 being the most restrictive.
Boris Johnson announced that non-essential shops, gyms, leisure centres, swimming pools, sports pitches, hairdressers, beauty salons, synagogues, churches and mosques will be allowed to reopen under all tiers. There are some varying conditions under each tier.
However, there are different rules for the hospitality industry, indoor entertainment industry, socialising and travel under each tier.
Hospitality and indoor entertainment
In Tier 1, bars, pubs and restaurants will operate table service only, and must stop taking orders at 10pm, before closing at 11pm. Indoor entertainment venues – such as cinemas, theatres, bowling alleys and casinos – will be allowed to stay open but live indoor performances will be limited to 50 per capacity or 1,000, whichever is smaller.
In Tier 2, alcohol may only be served in hospitality settings as part of a substantial meal, before last order at 10pm and venues being forced close at 11pm. Indoor entertainment venues can open with and social distancing and limits of 50 per cent capacity or 1,000 people.
In Tier 3, hospitality venues must close apart from delivery and takeaway. Indoor entertainment venues – such as cinemas, theatres, bowling alleys and casinos – will remain closed.
Under Tier 1, spectator sports can resume with a maximum crowd of 50 per cent of stadium capacity or 4,000 spectators, whichever is smaller.
Under Tier 2, it can resume with 50 per cent of capacity or 2,000 spectators, whichever is smaller.
Under Tier 3, it cannot resume.
Socialising, travel and overnight stays
Only those in Tier 1 areas will be able to meet people they don't live with indoors. They can also meet with people outdoors, subject to the rule of six.
In Tier 1, the stay home message is also being lifted although people will still be encouraged to minimise their movements and to work from home where possible.
Overnight stays will be permitted if they are limited to a support bubble, household or up to six people.
People in Tier 2 can't socialise with other households indoors but can meet people outside under the rule of six.
Overnight stays will only be permitted for those in the same household or support bubble and accommodation can open.
People will be encouraged to reduce the number of journeys they make and to avoid travelling into Tier 3 areas, except for reasons of education or work.
Those in Tier 3 can't mix with other households indoors, or in private and pub gardens. They can meet under the rule of six in outdoor public spaces, such as parks and sports courts.
People will be told to avoid travelling out of the area other than where necessary and to reduce the number of journeys.
No overnight stays will be permitted outside the local area, except for work or education, with accommodation to stay closed.
There are exceptions for childcare and support bubbles.
People are advised not to travel to and from Tier 3 areas.
Under all tiers, 15 guests will be allowed at weddings and civil partnerships, increasing to 30 for funerals.
But wedding receptions are banned in Tier 3.
Places of worship
Places of worship can reopen, but people must not interact with more than six people.
Under Tier 2 and Tier 3, people must not interact with anyone outside their household or support bubble at places of worship.
Setting out other measures that will be eased as the lockdown lifts, Mr Johnson said: “From next Wednesday, people will be able to leave their home for any purpose and meet others in outdoor public spaces, subject to the rule of six, collective worship, weddings and outdoor sports can resume, and shops, personal care, gyms and the wider leisure sector can reopen.
“But without sensible precautions, we would risk the virus escalating into a winter or New Year surge.”
On spectator sports, he added: “In Tiers 1 and 2 spectator sports and business events will be free to resume inside and outside with capacity limits and social distancing, providing more consistency with indoor performances in theatres and concert halls.
"We'll also strengthen the enforcement ability of local authorities, including specially trained officers and new powers to close down premises that pose a risk to public health."
On spectator sports, the official guidance states: “In Tiers 1 and 2, spectator sport and business events can now resume inside and outside with tight capacity limits and social distancing, providing more consistency with indoor performances in theatres and concert halls."
It goes on: “The Government will also introduce spectator capacity limits for sports stadia, business events and live performances in tiers where these are permitted.”
- When will the new system be introduced?
The national lockdown in England is due to end on December 2.
Ministers will set out what tier each area will be placed into on Thursday and MPs are expected to be given the vote to approve the new system in the days before it comes into force.
- Is the vote a done deal?
Not entirely - the Prime Minister will be wary of a rebellion from backbench Tory MPs who are opposed to new restrictions.
During a vote on the current four-week system earlier this month, 32 Conservatives rebelled to oppose the measures and 17 more, including former prime minister Theresa May, abstained.
A "Covid recovery group" led by former chief whip Mark Harper and ex-Brexit minister Steve Baker has been formed to resist new measures, with suggestions 50 Tories have enlisted.
But Labour has so far been supportive of the need for restrictions to slow the spread of Covid-19, and a full-scale Commons defeat on the plan is unlikely.
- How long will the new system last for?
The Government is optimistic that restrictions can be gradually reduced in the run-up to spring, providing vaccines are approved by regulators, allowing a plan for the rollout to begin next month before a wider programme in the new year.
But with no vaccines having been approved it is still not clear exactly when the rollout will be able to begin.
- What is expected over Christmas?
Several households - potentially three - could be allowed to create a bubble temporarily between December 22 and 28, with the plans covering all four nations of the UK, according to the Daily Telegraph.
Boris Johnson said the Government is working on a time-limited Christmas dispensation with the devolved administrations.
He told the Commons: “I can’t say that Christmas will be normal this year, but in a period of adversity time spent with loved ones is even more precious for people of all faiths and none.
“We all want some kind of Christmas, we need it, we certainly feel we deserve it. But what we don’t want is to throw caution to the winds and allow the virus to flare up again, forcing us all back into lockdown in January.
“So to allow families to come together, while minimising the risk, we’re working with the devolved administrations on a special time-limited Christmas dispensation, embracing the whole of the United Kingdom.”
- What were the details of the original three tier system?
Areas in the first tier - medium alert - were subject to the same national measures which were in force at the time across the country including a 10pm curfew for pubs and restaurants and a ban on most gatherings of more than six people.
Under the second tier - high alert - household mixing was banned indoors while the rule of six continued to apply outdoors.
Tier 3 - very high alert - banned social mixing both indoors and in private gardens, while pubs and bars were told to close unless they could operate as a restaurant.
Local leaders were to help determine whether other venues should be closed, such as gyms or casinos, in very high alert level areas.
But the system faced criticised as not being strong enough to reduce the spread of the virus.
- Why was the tier system criticised?
Labour leader Sir Keir Starmer said the toughest tier of restrictions was "a gateway to weeks and weeks, more likely months and months, of agony from which there's no likely exit".
Local leaders also complained that once an area was placed in Tier 3 it was not clear what it had to do to get out of it.
The British Medical Association (BMA) also said that the previous system was "inadequate" and did not contain the spread of the virus.
- Did the tier system work?
There has been some indication that the system helped in parts of the country.
Dr Susan Hopkins, a Public Health England director advising the Government's coronavirus response, said recently that Tier 1 restrictions had "very little effect", Tier 2 varied across areas and Tier 3, especially "Tier 3 plus", had reduced case numbers in the North West.
She said the Government may have to think about "strengthening" tiers "in order to get us through the winter months".
Experts on the Scientific Pandemic Influenza Group on Modelling (SPI-M), which advises the Government, believe infections will rise at the same rate as before if the same three-tier system is brought back in December.