Tougher restrictions may be needed in some areas of the country to curb the spread of a fast-spreading strain of the coronavirus.
That was the warning from the government's chief scientific adviser as he said the new variant is likely to 'spread in numbers'.
Speaking at the Downing Street press conference on Monday, Sir Patrick Vallance said: "The tier decisions are not ones for me, but I will say that the evidence of this virus is that it spreads easily, it's more transmissible.
"We absolutely need to make sure we've got the right level of restrictions in place.
"I think this is likely that it will grow in numbers of the variant across the country and I think it's likely therefore that measures need to be increased in some places in due course, not reduced.
"I think this is a case that it will spread more."
However, Prime Minister Boris Johnson said there was no evidence that the variant is 'any more dangerous' than existing strains.
It means there is 'nothing to suggest' that a vaccine will not work against it, he said.
Sir Patrick Vallance confirmed that the scientific evidence pointed in this direction.
He said: "The evidence that this can transmit more readily is becoming clear in terms of the data of the rapid spread of this virus across areas.
"The transmission is...substantially increased.
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"There is no evidence that the disease course is any different.
"So if you catch it the disease is the same, or looks the same as any other form of Covid infection.
"And in terms of the immune response, there's nothing to suggest this won't have the same susceptibility to antibody attack from vaccine or pre-existing infection as any other form.
"So no, at the moment, the vaccine looks as though it should be as effective and that's obviously being looked at," he said.
On Saturday, it was announced that a new Tier 4 lockdown would be introduced in London and parts of the South East after the new virus strain was identified there.
A huge jump in cases was recorded in the area.
Christmas Bubbles have been cancelled over the festive period in Tier 4 and all non-essential shops have been closed.
