The UK has recorded the biggest daily spike in coronavirus cases since the pandemic began, the latest data shows.
There were a further 35,928 positive cases recorded in the past 24 hours.
It takes the total number of cases in the country past 2 million.
The R rate of infection is now estimated to be between 1.1 to 1.2 with a growth rate of up to 4 per cent.
London accounts for a significant chunk of the new cases, having recorded more than 11,500 in a day.
Dr Yvonne Doyle, medical director at Public Health England, said: "This sharp and sudden increase is of serious concern.
"Most of the new cases reported today are concentrated in London and the South East, although it is too early to tell if this is linked to the new variant. "
"What we do know is that the way to control this virus is the same, whatever the variant. It simply will not spread if we avoid close contact with others. Wash your hands, wear a mask, keep your distance from others, and reduce your social contacts.
"By working together we have tackled this virus before. By holding the line over the next few weeks, it is possible we can do so again, as we continue to roll out the vaccine to the most vulnerable."
Of the 32,155 new positive cases reported for England on Sunday, the overwhelming majority (95%) were tests conducted in the last four days."
The Government also said a further 326 people had died within 28 days of testing positive for Covid-19 as of Sunday, bringing the UK total to 67,401.
Separate figures published by the UK's statistics agencies for deaths where Covid-19 has been mentioned on the death certificate, together with additional data on deaths that have occurred in recent days, show there have now been 83,000 deaths involving Covid-19 in the UK.
A further ten people have died in Greater Manchester's hospitals after testing positive for coronavirus.
The region's hospital death toll now stands at 4,029, according to the latest NHS figures.
