The UK recorded 51,459 new Covid cases in the last 24-hour period, according to official figures released on Monday.
That is up by nine per cent on the day before and brings the seven day total to 330,918 positive cases.
It is the highest number of daily cases recorded on a Monday, when figures are usually lower after the weekend, since October 18 when there were 56,712 positive tests.
Figures from the official daily summary show there were 41 deaths in the last 24 hours, which is down slightly by 0.2 per cent, and brings the seven day death toll to 836 deaths within 28 days of a positive test.
Separate figures published by the Office for National Statistics show there have now been 170,000 deaths registered in the UK where Covid-19 was mentioned on the death certificate.
The government figures also showed a total of 51,118,266 first doses of Covid-19 vaccine had been delivered in the UK by December. This is a rise of 21,955 on the previous day.
Some 46,557,413 second doses have been delivered, an increase of 27,166.
A combined total of 20,580,644 booster and third doses have also been given, a day-on-day rise of 290,165.
Separate totals for booster and third doses are not available.
The emergence of the new coronavirus variant known as Omicron has already impacted travel rules and sparked a return to compulsory mask-wearing on public transport.
Some 336 cases of Omicron – also known as B.1.1.529 – were confirmed in the UK on Monday and the EU’s agency for infectious disease control has already warned it could become the dominant strain in Europe within months.
The University of East Anglia academic told BBC Breakfast: “How it’s likely to spread in the UK is still uncertain.
“But I think the early signs are it will probably spread quite quickly and probably start outcompeting Delta, and become the dominant variant probably within the next weeks or a month or so at least.”
