The UK is in a “very dangerous situation” in its battle against coronavirus, facing a “grim and depressing picture” of rising infections and deaths as millions more were placed under the tightest tier of restrictions.

The bleak picture painted on Wednesday by Jonathan Van-Tam, England’s deputy chief medical officer, followed news of the regulatory approval of the Covid-19 vaccine from Oxford University and AstraZeneca, which has raised hopes that the virus could be defeated.

But that optimism faded as the UK recorded 981 coronavirus related deaths, the highest daily figure since April. Infection rates soared to 50,023 new cases.

The alarming surge in deaths spurred new measures to limit the spread of the virus.

The return of secondary schools after the Christmas break has been delayed as ministers announced that by Thursday almost four-fifths of England would be living under the toughest tier 4 restrictions. Mr Johnson warned that the measures could last until April.