The Omicron variant of coronavirus appears to be “more transmissible” than the Delta strain, Boris Johnson told ministers, as the UK reported its highest weekly number of new Covid-19 cases since January.
A total of 336,893 new Covid-19 cases have been reported in the past seven days, including 45,691 on Tuesday, Government figures show – the highest since the week to January 16.
Official figures also showed 101 additional confirmed cases of the Omicron variant have been reported across the UK, taking the total to 437.
At the weekly Cabinet meeting the Prime Minister said it was “too early to draw conclusions on the characteristics of Omicron” but “early indications were that it was more transmissible than Delta”.
The Prime Minister’s official spokesman said there was no Cabinet debate on whether to introduce Plan B to control the virus this winter in England.
But in Scotland, First Minister Nicola Sturgeon said guidance to work from home would continue until mid-January and she warned further coronavirus restrictions could not be ruled out due to an increase in Omicron cases.
As a result of the “very significant risks posed by Omicron”, she said it was “important to keep the need for any additional protections under daily review”.
She said the time for cases to double “may be as short as two to three days” and the R of the variant – the number of people someone with Omicron is likely to infect – “may well be over two”.
Northern Ireland confirmed its first three cases of the variant on Tuesday with the Department of Health saying two cases in the greater Belfast area and a third unconnected case in the South Eastern Trust area all had a link to travel from Great Britain to Northern Ireland.
In Wales, health minister Eluned Morgan said “we are expecting a significant wave of Omicron to hit”.
Michael Gove is expected to meet with the first ministers of Scotland, Wales and Northern Ireland on Thursday to discuss the approach to the Omicron variant.
The Prime Minister believes the booster jab campaign is the best defence against both new and existing variants of coronavirus.
The latest figures showed 329,165 booster doses were reported on Tuesday.
“The booster programme is the fastest in Europe, I think we have done more boosters than any comparable country,” Mr Johnson told reporters.
“That doesn’t mean it couldn’t go faster.”
Labour leader Sir Keir Starmer has demanded a 500,000 daily target for top-up jabs and said: “We are in a race now between this booster regime and the new variant.
“The Government should have acted weeks ago, it absolutely now needs to ramp this up and ramp it up immediately.”
Meanwhile Tim Spector professor of genetic epidemiology at King’s College London, said early data suggested cases of the coronavirus mutation are doubling every two days, putting it on course to overtake some of the 11 African countries on the travel red list.
New rules came into force in the early hours of Tuesday requiring travellers from all destinations to take a pre-departure test before heading to England. They will not be able to travel if they test positive.
Professor Spector told BBC Breakfast there was “very little point” in having travel restrictions if case numbers exceeded those in red list countries.
He said there were probably 1,000 to 2,000 Omicron cases, because testing was “missing a lot” of them.
“We are expecting this to be doubling about every two days at the moment, so if you do your maths – assume it’s 1,000 at the moment, and you think it’s going to be doubling every two days, you can see that those numbers are going to be pretty (high) certainly in about 10 days’ time.
“By that time we’ll probably have more cases than they will in some of those African countries.”
Dr Jeffrey Barrett, director of the Covid-19 genomics initiative at the Wellcome Sanger Institute, said he thought Omicron would take over from Delta in the UK as the dominant variant of coronavirus “within a matter of weeks”.
He told BBC Radio 4’s Today programme: “I think we can now say that this variant is spreading faster in the UK than the Delta variant at the same time, and that’s something that I think was unclear until very recently.
“The fact that so far we have seen not very many severe cases of Omicron, maybe because it is infecting these individuals with some amount of immunity, and that’s good news that they aren’t having tonnes of severe disease, but I think it is too soon to assume that fundamentally Omicron is more mild than, say, Delta.”
The latest official update showed a further 180 people had died within 28 days of testing positive for Covid-19.
Separate figures published by the Office for National Statistics show there have now been 171,000 deaths registered in the UK where Covid-19 was mentioned on the death certificate.