The UK has recorded more than 37,000 Covid infections amid fears over the 'Nu' variant which has now reached Europe.
Data released by the Department of Health this afternoon shows a further 37,681 recorded infections in the latest 24 hour period.
That is a 5.8 percent decrease on last Sunday's total of 40,004 positive cases.
While a further 51 people died within 28 days of testing positive today in the UK, the data also shows.
It's a decrease on this time last week's 61 infection-related fatalities.
In total, there are 10,146,915 cases in the UK and there have been 144,775 deaths.
It comes after UK Covid cases surged above 50,000 per day again this week.
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The UK Health Security Agency said on Sunday that there are three cases of the new Omicron variant in Britain, adding that the individual, who was no longer in Britain, was linked to travel to Southern Africa.
UKHSA said that while in Britain, the individual was in Westminster in central London.
Jenny Harries, chief executive of UKHSA, said in a statement: "It is very likely that we will find more cases over the coming days as we are seeing in other countries globally and as we increase case detection through focused contact tracing."
This follows the news that Spain has announced that unvaccinated British tourists will be banned from entering, after Portugal said even double-jabbed tourists would need proof of a negative test to cross the borders.
The tightening-up of regulations governing entry to the UK’s favourite foreign holiday destination comes into force on Wednesday, ending an exemption which means travellers without their Covid jabs could enter Spain with a negative test or proof of recovery from Covid.
The decision was taken before confirmation that the new Omicron coronavirus variant had been detected in several European countries.
Boris Johnson has reacted to the Omicron threat by enforcing day-two PCR tests for arrivals in Britain and making facemasks compulsory in shops and trains.
Fears over the latest incarnation of Covid shot up rapidly when a patient in Belgium fell ill with the B.1.1.529 variant, first detected in South Africa.
Belgian Health Minister Frank Vandenbroucke said: "We have one case of this variant that is confirmed. It's someone who came from abroad."
The patient has no known links with South Africa, but had travelled to Belgium from Egypt.
Marc Van Ranst, whose laboratory works closely with Belgium's public health body Sciensano, said the person first developed symptoms on November 22.
Flights from South Africa, Namibia, Lesotho, Botswana, Eswatini and Zimbabwe were temporarily banned from noon yesterday and UK travellers told to quarantine.
The red list was previously scrapped earlier this month when all countries were taken off it.
Scientists sounded the alarm on Thursday night over the B.1.1.529 variant, which has the potential to evade immunity built up by vaccination or prior infection - and has been dubbed "worst we've seen so far".
Three cases have been identified so far in Britain and officials have raised concern over a rapid rise in cases in South Africa.
People who have arrived from the country in the last 10 days will be invited to take a test.
On confirming the ban, Health Secretary Sajid Javid said the new strain "may be more transmissible" than the Delta strain and "the vaccines that we currently have may be less effective".