Scientists suspect the final planned stage out of lockdown next month could be delayed by a surge in UK cases of the highly transmissible Indian Covid-19 variant – which are thought to have more than tripled in a week.
Members of the government’s scientific advisory committee, Sage, have been called to an urgent meeting on Thursday to assess the threat.
Figures due out on Thursday are expected to confirm a total of 1,723 cases of B1617.2, one of three mutations fuelling India’s spiralling death toll.
The prime minister has warned that the strain is “of increasing concern” in the UK.
A member of Sage told the i paper that while next Monday’s step three of easing of restrictions in England would go ahead, concerns over the variant might increase ahead of the fourth and final step on 21 June and that “a delay is possible”.
The scientists tracking new variants have identified the 1,723 cases, and while some may be duplicates, if the figure is confirmed by Public Health England, this would be more than three times last week’s number of 520.
Health officials have designated two of the Indian Covid variants – known as B1617.1 and B1617.3 – as “under investigation”. A third, B1617.2, has been upgraded and is now a “variant of concern.”
The variants are particularly spreading in Bolton, Greater Manchester, where enhanced testing and a vaccine drive are being rolled out.
Mr Johnson says the government is looking at all possible solutions to tackle the surge there. “It may be more transmissible ... maybe even considerably more transmissible,” he said.
Secondary school pupils could be told to continue to wear face masks after the policy is dropped for the rest of England from next Monday.
There are also clusters in Blackburn and evidence of rising community transmission in parts of London.
The prime minister told the Commons on Wednesday the nation faces the threat of new variants which, if they prove highly transmissible or elude protection from vaccination, could produce a situation that is worse than that in January, with a resurgence of hospitalisations and deaths.
Ministers have not ruled out introducing local lockdowns in areas where the Indian variant is increasing.
This article was amended on 13 May 2021. It originally stated that all three variants were under investigation. However, one variant has been upgraded and is “of concern,” and the article has been amended to reflect this.