Most of the country is now in the upper two tiers where shops, hairdressers, beauty salons and places of worship can reopen. But pubs and restaurants face strict limits in Tier 2 and closure in the topmost Tier 3.
Johnson told the House of Commons that a lockdown imposed on November 5 had succeeded in levelling off the coronavirus infection rate in England, but that there was "a compelling necessity" for further restrictions.
"What we cannot do is lift all of the restrictions at once, or move too quickly, in such a way that the virus would begin to spread rapidly again," triggering a new lockdown in January, he said.
The new measures are to be reviewed every two weeks and restrictions will be eased for five days over Christmas so that families can get together. Other parts of the UK — Scotland, Wales and Northern Ireland — are all following their own local restrictions to curb the spread of the virus.
Britain has had Europe's deadliest Covid-19 outbreak, with more than 59,000 confirmed virus-related deaths.
But many Conservative MPs say the economic damage of the restrictions is increasingly outweighing the public health benefits. They say the Government has not provided data to show the need for the restrictions, and is proposing a complicated and unfair system.
Conservative MP Andrea Leadsom said she would not vote for the measures because she was not convinced they were "a lesser of all evils."
A humble foodstuff, the Scotch egg, has become a symbol of the discontent and confusion around the new rules. Livelihoods may depend on whether the popular concoction of a boiled egg wrapped in sausage meat and encased in breadcrumbs is a snack or a meal.
Pubs in Tier 2 areas can open and serve alcohol but only alongside a "substantial meal." Ministers have given mixed messages about whether a Scotch egg fits the bill.
Cabinet Minister Michael Gove told broadcaster ITV that "as far as I'm concerned, it's probably a starter," but later said "I do recognise that it is a substantial meal."
Critics say the Scotch egg debate — and related disputes about the status of sausage rolls, pork pies and pizza — shows the measures are inconsistent and open to abuse.
In an attempt to assuage critics, Johnson said pubs that have to stay closed will receive 1000 pounds in recognition of "how hard they have been hit by this virus in what is typically their busiest month."
But Simon Emeny, chief executive of brewers Fuller, Smith and Turner, said that would not be enough to solve "the financial Armageddon" that many English pubs are facing.
- AP
