The government has raised fears it could bring back the controversial “tiers” system in England to tackle the Indian variant.
No10 refused to rule out reintroducing local lockdowns – which last year were seen by many as a failure – as areas like Bolton battle the B.1.617.2 strain.
It comes hot on the heels of Matt Hancock warning “we don’t rule out” local restrictions to tackle the virus.
England had three “tiers” with different rules for gatherings and pubs last year. But eventually Boris Johnson plunged the country into a month-long November lockdown anyway.
When England emerged it struggled through a month on a new four-tier system before having to go into lockdown again.
Boris Johnson’s official spokesman was asked if ministers would consider a return to a tiered system in future.
He replied today: “I don’t want to get ahead of where we are at the moment and start getting into hypothetical situations.
“As the Prime Minister has set out, we’ve moved as a country into step three, albeit with a very targeted increase in surge vaccinations and testing in these areas where we’re seeing rises.
“That’s what we want to proceed with if at all possible but we don’t want to rule anything out.
“And I think until we have more data and more evidence, we won’t be making those judgments.”
Yesterday Health Secretary Matt Hancock was asked if parts of England with higher cases or hospitalisations could have different restrictions.
He told Sky News: “Yes, well, we don’t rule that out.
“The approach that we’re taking in Bolton and in Blackburn is to absolutely pile in testing and vaccinations to try to get on top of this.
“When we had an outbreak of the South African variant in South London last month we put in huge amounts, hundred of thousands of tests in surge testing.
“People came forward in their droves across Southwark and Lambeth and Wandsworth and we got that under control.”
He added: “Given though that Bolton has been in some kind of a lockdown for a year, it’s not a step we’d want to take,
“But of course we might have to take it and we will if it’s necessary to protect people.”
No10 today confirmed major updates on weddings and the end of social distancing that were due this month may now be delayed by the Indian variant of Covid.
Boris Johnson’s official spokesman said the Prime Minister can no longer promise a review of social distancing rules will report back by May 31.
He also refused to stand by Mr Johnson’s pledge to give weddings 28 days’ notice before resuming in full, which would have meant an update on around May 24.
The update comes just days after Mr Johnson made the two pledges – and are the clearest sign yet that the final step of England’s roadmap could be delayed.
While full-size weddings and the end of social distancing laws would not have happened before June 21 at the earliest, Boris Johnson had hoped to give extra notice – more than the one-week notice for the rest of “step four” of his roadmap.
But after he made those promises, new data last Thursday showed the B.1.617.2 strain – originally found in India – had more than doubled in the UK in a week to over 1,300 cases.
Scientists currently believe the strain is more transmissible than the Kent variant which swept through the UK around Christmas, but they do not know by how much.
Business Secretary Kwasi Kwarteng earlier insisted it was still “very likely” all restrictions will be able to end from June 21.
But Downing Street today stood by Boris Johnson’s comments from Friday, that the new variant could have to push back the plans for June 21.
The PM’s spokesman said: “As the Prime Minister first said on Friday, the variant first identified in India could pose serious disruption to this progress and could make it more difficult to move to step four on the earliest date of June 21.
“So that’s why we’re taking the action now to clamp down on it. Our decision will be based on the very latest data and we want to allow as much time as possible to assess this.
“So we will set out plans as soon as the data allows.”