Prime Minister Boris Johnson said on social media that it was a “huge national achievement” and praised the NHS staff, volunteers and armed forces for their work in the vaccine rollout.
Health Secretary Matt Hancock added in a video message: “I’m absolutely delighted that over 20 million people have now been vaccinated across the UK – it’s absolutely fantastic.
“I want to thank every single person who’s come forward to get the jab because we know with increasing confidence that the jab protects you, it protects your community and it also is the route out of this for all of us.”
Six cases of the new Manaus variant of coronavirus, which is more contagious and may be more resistant to vaccines, have been found in Britain, three in England and three in Scotland.
Coronavirus vaccine in numbers: UK reaches 20 million vaccinations
Questions were raised over how the variant from the Brazilian city was identified in a Covid-19 test of someone who did not fill in a registration form with their name and details.
In a round of interviews, Nadhim Zahawi, the vaccinations minister, admitted that the Government had no idea who the carrier is, where they live, whether the carrier had travelled to Brazil or not, or were self-isolating or potentially spreading the virus.
Labour leader Keir Starmer said the discovery of the Brazilian coronavirus variant in the UK shows the Government has not “secured our borders in the way we should have done”.
The Prime Minister defended the Government’s measures to prevent new variants being imported into the country.
He told reporters: “We have got one of the toughest border regimes anywhere in the world for stopping people coming in to this country who may have variants of concern.”