More areas of England are likely to enter the highest level of tier 4 restrictions in the new year as the country braces for the spread of the new strain of coronavirus, the government’s chief scientific adviser has warned. Patrick Vallance said it was “important to get ahead” of the new variant and told a Downing Street press conference that it was “likely” that tighter measures would be needed in some parts of the country rather than any relaxation of the rules.

Sir Patrick confirmed the new strain, labelled B.1.1.7, spread “substantially” more quickly than previous variants, with early studies suggesting it could be 71per cent more transmissible. He said B.1.1.7, which appeared to originate in Kent, was already present across many parts of the country and that the”inevitable period of mixing” over Christmas would make matters worse.

His warning came as Boris Johnson raised doubts about whether school children in all parts of England would make a staggered return to their classes after the Christmas break as originally planned. The prime minister said schools would be kept open “if we possibly can”, but said that it was important to respond the evolution of the virus and to “keep things under constant review”. Hancock warns of tough restrictions for months amid new Covid strain

As a bleak year drew to a close, Mr Johnson avoided questions about his tendency to “over-promise and underdeliver” when it came to his approach to tackling the virus. He responded by claiming that some people had wanted to keep the lockdown in place for months while he had been right to make the case for easing it.

He repeated his promise of a brighter future offered by the rollout of the mass inoculation programme. “Nowwe have a vaccine coming, we can look forward to a very different world in this country from Easter onwards,” he said, adding that 500,000 people had already received their first dose.

Sir Patrick said the vaccine “looked like it should be as effective” against the new strain, although research was still under way.