The number of new Covid-19 infections in Britain is estimated to be shrinking by as much as 4 per cent a day, Reuters quoted the government as saying on Friday, a sharp reversal in the trajectory of the pandemic suggesting national lockdowns were beginning to take effect.

England and Scotland announced new restrictions on Jan 4 to stem a surge in the disease fuelled by a highly transmissible variant of the coronavirus, which has led to record numbers of daily deaths and infections this month.

The latest estimates from the health ministry suggest that the number of new infections was shrinking by between 1pc and 4pc a day. Last week, it was thought cases were growing by much as 5p, and the turnaround gave hope that the spread of the virus was being curbed, although the ministry urged caution.