British Prime Minister Boris Johnson on Monday ordered England into a new national lockdown to try to slow a surge in COVID-19 cases that threatens to overwhelm parts of the health system before a vaccine programme reaches a critical mass.

Johnson said a new, more contagious variant of the coronavirus was spreading at great speed and urgent action was needed to slow it down.

“As I speak to you tonight, our hospitals are under more pressure from COVID than any time since the start of the pandemic,” Johnson said in a televised address to the country as he ditched his regional approach to fighting the pandemic.

“With most of the country already under extreme measures, it’s clear that we need to do more together to bring this new variant under control.

“We must therefore go into a national lockdown, which is tough enough to contain this variant. That means the government is once again instructing you to stay at home.”

Johnson said the measures would include school closures from Tuesday and rules requiring most people to stay at home apart from essential shopping, exercise and other limited exceptions.

He said that if the timetable of the vaccination programme went as planned and the number of cases and deaths responded to the lockdown measures as expected, it should be possible to start moving out of lockdown by the middle of February.

However, he urged caution about the timetable.

As Britain grapples with the world’s sixth highest death toll and cases hit a new high, the country’s chief medical officers said the spread of COVID-19 risked overwhelming parts of the health system within 21 days.

The surge in cases has been driven by the new variant of COVID-19, officials say, and while they acknowledge that the pandemic is spreading more quickly than expected, they say there is also light at the end of the tunnel – vaccinations.

Johnson’s government earlier touted a scientific “triumph” as Britain became the first country in the world to start vaccinating its population with Oxford University and AstraZeneca’s COVID-19 shot.

Dialysis patient Brian Pinker on Monday received the first vaccination outside of a trial.

“I am so pleased to be getting the COVID vaccine today and really proud that it is one that was invented in Oxford,” said the 82-year-old retired maintenance manager, just a few hundred metres from where the vaccine was developed.

But even with the vaccines being rolled out, the number of COVID-19 cases and deaths keep rising.

More than 75 000 people in the United Kingdom have died from COVID-19 within 28 days of a positive test since the start of the pandemic.

A record 58 784 new cases of the coronavirus were reported on Monday.

Moving a few hours ahead of Johnson, Scottish First Minister Nicola Sturgeon imposed the most stringent lockdown for Scotland since last spring.

The devolved administration in Wales said all schools and colleges there should move to online learning until January 18.