– Christopher Furlong/PA
At a Downing Street press conference, he warned it is clear the new strain is “growing much faster” than the delta variant.
Case, and cases of Omicron could be doubling every two or three days as he strengthened England’s rules to slow the spread of Covid-19.
Mr Johnson said Christmas parties and nativities could go ahead, but urged people to “exercise due caution” and get their booster jabs.
Mandatory mask wearing will be extended to indoor public venues including cinemas, theatres and places of worship from Friday – but will not be required in pubs and restaurants, while the guidance to work from home where possible will return on Monday.
The NHS Covid pass, which can be obtained by having two vaccines or a negative lateral flow test, will be introduced for entry into nightclubs and other large venues from December 15, as Mr Johnson set out the “proportionate and responsible” measures.
But he was forced to insist the public understands the “vital importance” of the measures as he faced questions at the hastily-arranged Downing Street press conference over how they can accept his rules amid anger over allegations Downing Street staff broke Covid rules in a Christmas party last year.
He added: “The best way to ensure we all have a Christmas as close to normal as possible is to get on with Plan B, irritating though it may be it is not a lockdown.
“We don’t want nativity plays to be cancelled, we think it’s okay currently on what we can see to keep going with Christmas parties but obviously everybody should exercise due caution.”
The Prime Minister also denied suspicions he had brought forward the announcement to divert attention from the row and the leaked video showing No 10 staff laughing about restrictions after the alleged party, which on Wednesday forced the resignation of Government aide Allegra Stratton.
“Just imagine the counterfactual, colleagues say, or people say, we’re somehow making this announcement to coincide with events in politics well actually imagine if this step were to be delayed because of political events of one kind or another, what would people say then? You’ve got to act to protect public health when you’ve got the clear evidence,” he said.
Stood beside Mr Johnson on the same podium where Ms Stratton made the remarks, England’s chief medical officer Professor Chris Whitty acknowledged the anger when people feel “it’s unfair”.
But he added that was “quite different from people wanting to actually know what’s going on and then make decisions”.
Simultaneously in the Commons, Health Secretary Sajid Javid warned there are 568 cases of omicron confirmed, but that the true figure is estimated to be “probably closer to 10,000”.
But he also faced heckles of resign as he updated MPs on the new restrictions, which he said would be reviewed on 5 January.
Covid health certificates will apply to unseated indoor venues with more than 500 attendees, and outside where there are more than 4,000 people.
The Prime Minister said passes can be obtained with a negative lateral flow test or by having had two doses of a vaccine, but hinted this could change by saying “we will keep this under review as the boosters roll out”.
MPs are expected to be given a vote on the measures on Tuesday, during which a number of Tory rebels who have been angered by restrictions are expected to oppose the Government.
But shadow health secretary Wes Streeting said Labour supports the new restrictions as being “in the national interest”, meaning they will almost certainly be approved in the Commons.
Senior Whitehall sources said that a meeting of the government’s Covid-O committee has been called to discuss the restrictions while Professor Neil Ferguson of Imperial College London, a member of the Scientific Advisory Group for Emergencies (Sage), said that a new UK-wide lockdown to deal with the threat of omicron could no longer be ruled out despite Britain’s high rate of vaccination.
In a press conference on Saturday 27 November responding to the identification of the new omicron variant, the prime minister had already announced that face masks would once more be mandatory in shops and on public transport, more countries would be added to the travel “red list” and new arrivals from overseas would be required to take a PCR test and potentially self-isolate for 10 days.
But he had stopped short at that point of fully implementing the Plan B contingency strategy drawn up in September.
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