This means shutting down pubs, bars, and other hospitality businesses, as well as a ban on household mixing indoors.
Forthcoming guidelines are expected to lay out what constitutes that food, ruling out venues getting around a shutdown by serving token snacks alongside alcohol.
In addition to these restrictions, in areas on high alert - including north-east England, much of the North West and parts of the Midlands, along with West and South Yorkshire - different households are not allowed to mix indoors.
These include the "rule of six", which limits most indoor and outdoor social gatherings to six people, and the 10pm curfew for pubs and restaurants.
The Prime Minister said agreement has been reached with leaders in Merseyside, explaining it will be in the "very high alert" level from Wednesday - with gyms, leisure centres, betting shops, adult gaming centres and casinos also closing.
Andrew Hayward, professor of infectious disease epidemiology at University College London and a member of Sage, said he did not think the restrictions included in Tier 3 would result in the R rate being pushed below one, meaning the virus was likely to still spread at pace.
Johnson says the new system is created to avoid another national lockdown which he says would cause long term economic damage.
"This is not how we want to live our lives", the Conservative leader, who himself was hospitalised with coronavirus in April, told the House of Commons.
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After the committee completes the hearings, which is expected to happen on Thursday, Graham can move for a committee vote. The Supreme Court is scheduled to hear arguments on November 10 regarding whether the whole law should be tossed out.
Pubs and bars will be closed unless they are serving substantial meals and there is also guidance against travelling in and out of the area.
A source told the newspaper Mr Hancock and Mr Gove were pushing "for more restrictive measures" but of a less intense nature so local authorities could add to them depending on the individual situation.
In another document which could prove highly damaging to the government, the SAGE group of scientists said that the £12 billion "test-and-trace" programme, which Johnson has described as "world-beating" is having only a "marginal" impact on reducing the spread of the virus because it is not tracing enough people, and many of those contacted are simply ignoring advice to self-isolate.
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German Chancellor Angela Merkel hosted a cabinet-level meeting Monday, though there are unlikely to be any decisions on new measures until she meets with the premiers of the country's 16 states on Wednesday. Health officials say that Britain is at the tip of the outbreak, with strong action needed to prevent hospitals from being overwhelmed at a time when they are already busy with flu and other winter conditions.
England's Deputy Chief Medical Officer, Jonathan Van-Tam, said Monday that although northern England has the highest rates of infection, cases are on the increase across the world.
Manchester intensive care consultant Jane Eddleston said 30% of critical care beds were taken up with COVID-19 patients and this was starting to affect healthcare for others.
"This is a nationwide phenomenon now that rates are changing upwards across the United Kingdom", he said.
He said the rise in coronavirus cases is now being seen "nationwide" and is not exclusively a problem for northern England.