Another 144 people have died after testing positive for coronavirus and a further 6,035 new cases have been reported.
This compares to the 290 coronavirus deaths and 7,434 new infections recorded on Saturday.
Although weekend figures are generally lower due to delays in reporting, significantly, these are the lowest respective daily figures for some months.
It is the lowest number of daily deaths since 136 were announced on 2 November – and the lowest figure for new cases since 28 September, when there were 4,044.
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The latest figures come as Health Secretary Matt Hancock confirmed 20 million people have now received their first dose of a vaccine.
Sunday’s figures show 20,089,551 people have had their first dose while 796,132 people have had both.
The total number of people who have died within 28 days of testing positive for coronavirus in the UK now stands at 122,849.
Prime Minister Boris Johnson said Sunday’s vaccine milestone was a “huge national achievement” and praised the NHS staff, volunteers and armed forces for their work in the roll-out.
He tweeted: “20 million people across the UK have now got the jab – a huge national achievement and a testament to the tireless work of NHS staff, volunteers, the Armed Forces & many more.
“I urge everyone to get the jab when called. Every jab makes a difference in our battle against COVID.”
Mr Hancock had earlier said reaching the milestone was a “magnificent achievement for the country”.
He also urged everyone eligible for the vaccine to come forward and said: “Every jab in the arm is another life soon to be protected from this awful disease and means we are a step closer to returning to our normal lives.”
The milestone was reached as nearly two million people aged 60 to 63 in England are being invited to book a coronavirus jab, with the letters due to start arriving on Monday.
NHS England said the letters will explain how people can make an appointment through the national booking service.
They added that the letters have been sent out after more than three in four people aged 65 to 70 took up the offer of a vaccination.