Britain on Wednesday reported more than 1,000 Covid-related deaths for the first time since April.
The country recorded 1,041 deaths within 28 days of people testing positive for the virus, the Department of Health said. Official data also showed 62,322 new infections, a new daily record.
England and Scotland are in new national lockdowns to help stem the latest wave of the virus, which has been blamed on a new, more transmissible variant of the coronavirus.
On Tuesday, the UK recorded 60,916 new coronavirus infections and 830 deaths.
Britain has been among the worst-hit countries and at 77,346 now has the highest death toll in Europe.
Prime Minster Boris Johnson ordered the new lockdown for England on Monday, warning the NHS would be overwhelmed if urgent action was not taken.
Under the new rules, schools are closed to most pupils, people should work from home wherever possible and all hospitality venues and non-essential shops are closed.
Health Secretary Matt Hancock on Wednesday urged legislators to back the new measures as he revealed more than 30,400 patients were being treated in hospital for Covid-19.
"If we don't act now, the NHS won't be able to cope," he said. "Winter will be difficult but we now know what a way out looks like."
He said 1.3 million people had been vaccinated and the most vulnerable people, including those over 80 and in care homes, should be inoculated by mid-February.
The Covid-19 restrictions, he said, would be relaxed slowly and the current measures could possibly last until March.