Scientists are racing to answer three crucial questions: whether the new strain is indeed transmitting more readily as suspected; if it makes people sicker and the prognosis for those who catch it worse; and whether vaccines would be effective against it.

When the existence of the mutation was first mentioned by the Health Secretary Matt Hancock early last week much of the reaction of scientists was sceptical. However, this has changed markedly in the last 24 hours with several leading scientists saying it posed a serious challenge to the management of the epidemic.

“The new strain of Covid-19 is worrying and real cause for concern and extra caution,” said Sir Jeremy Farrar, director of Wellcome Trust and a member of SAGE on Twitter. “Research is ongoing to understand more, but acting urgently now is critical. There is no part of the UK and globally that should not be concerned. As in many countries, the situation is fragile”.