The development comes after a case of the South Africa coronavirus variant was found.
Half of the "variants under investigation" and "variants of concern" were first identified in Britain. This could be why.
As of Monday there are 170 reported cases of the variant, but the real number is likely much higher.
Health secretary Matt Hancock gives a coronavirus press briefing as the UK reports 12.2 million people have been vaccinated, with another 333 deaths in the past 24 hours. Earlier, South Africa temporarily halted the rollout of the Oxford AstraZeneca vaccine after one report suggests its effectiveness against the South African variant was greatly diminished.
A really simple guide to the Covid variant that’s got everyone talking.
It comes as scientists working on the Covid vaccine raise the prospect of having a booster dose available by the autumn.
The research, due to be published on Monday, looked into the E484K mutation of the coronavirus.
Some cases of the South African coronavirus variant in the UK can't be linked to travel.
Are new variants an alibi for past mistakes, or proof that a different approach works?
Matt Hancock urged people in areas where the variant has been found to “take extra special precautions” under lockdown rules.