The UK saw the highest daily increase in coronavirus cases today with 35,928 new infections.
Another 326 deaths were also announced today – more than twice as many as last Sunday.
Typically, the number of deaths announced by the Department of Health is lower on a Sunday due to a delay in reporting.
It comes after 534 deaths and another 27,052 cases were reported yesterday.
The second largest increase in registered coronavirus cases occurred on Thursday when 35,383 new infections were announced.
However, this included 11,000 additional cases that were not previously reported due to system maintenance in Wales.
The coronavirus situation in the UK has worsened significantly in recent weeks.
173,263 new cases were reported across the UK in a seven-day period last week.
That is an increase of 38% compared to the previous week.
Yesterday, Boris Johnson attributed the rise in infections to a mutated form of the coronavirus.
The prime minister announced new lockdown measures to combat soaring case rates, including closing non-essential stores in Tier 4 areas.
Today Health Secretary Matt Hancock said he was “very concerned” about the NHS, which now treated almost as many hospitalized patients with the disease as it did at the height of the first wave of the pandemic in April.
“The new line is out of control and we need to get it under control,” he told BBC1’s The Andrew Marr Show.
“We don’t know how long these measures will be in place. It may be some time before we can get the vaccine going.”
He said more measures were needed to control the new variant than the original coronavirus.
“We know that with this new variant you can more easily detect a smaller amount of the virus that is present,” he told Sky News’ Sophy Ridge on Sunday.
“We know this because we know that in November in areas where this new variant began, cases continued to rise in Kent, while in the rest of the country the November lockdown worked very effectively.
“It is a huge challenge until we can get the vaccine in place to protect people. This is what we have to do in the next few months.”
Mr Hancock insisted they acted “very quickly and decisively” after ministers were informed on Friday by scientists from the government’s Advisory Group on New and Emerging Respiratory Viruses (Nervtag) that the VUI strain 202012/01 was spreading faster .
However, Sir Keir Starmer said the alarm bells had “rung for weeks” but Mr Johnson – who said Wednesday it was “inhuman” to cancel Christmas – had repeatedly failed to act.
“It is gross negligence on the part of a prime minister who has been caught behind the curve again,” said the Labor leader.
“At the center of the problem here is a prime minister who just doesn’t want to be unpopular and therefore doesn’t make the tough decisions that are necessary until he’s forced to do so in hour 11.
“We cannot go on like this. I think it is very important that the Prime Minister apologize to the people for his handling of this episode of the pandemic.”