More than 20 million people in the UK are now fully vaccinated against Covid-19 after receiving both doses of vaccine.
The latest government figures show 20,103,658 people have now received both jabs, just over 38% of the adult population of the country.
Health Secretary Matt Hancock said he was "delighted" the landmark figure had been reached and thanked "everyone who is working incredibly hard to make this happen".
He urged people to "come forward and get the jab" when invited to do so.
The latest update also showed the UK has recorded a further four Covid-19 deaths and 1,926 new confirmed cases. Sunday's update brings the total death toll to 127,679 and the total number of cases to 4,450,777.
Separate figures published by the UK’s statistics agencies show there have been 152,000 deaths registered in the UK where coronavirus was mentioned on the death certificate.
The figures come ahead of the easing of lockdown measures across UK nations next with, with the health secretary insisting relaxing the rules is “appropriate” despite warnings from scientists and medics.
ITV News Correspondent Dan Rivers reports on the concerns about Monday's easing of lockdown:
Cases of the Indian Covid variant are spreading in the UK, especially in the north-west regions, prompting worries about pressing ahead with the roadmap.
The government has said it will speed up its efforts to give second Covid vaccine doses for certain groups of people to try and tackle the rise of the variant across the country.
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Three new Covid deaths were reported in England on Sunday.
Scotland has recorded another 292 cases of coronavirus and no new deaths.
The death toll in the country remains at 7,664.
With the exception of Glasgow and Moray, mainland Scotland is due to move from Level 2 to Level 3 restrictions on Monday.
One further Covid death was reported in Wales' update on Sunday, along with 54 new confirmed cases.
It brings the total number of cases to 212,149 and the death toll to 5,559.
The Department of Health reported 109 new positive tests and no new deaths.
As of Friday 14 May, the total death toll stands at 2,149.