Health Secretary Sajid Javid has said face masks will be compulsory in shops and on public transport in England from Tuesday in response to the new Omicron variant.
It brings England in line with other parts of the UK. The PM also announced earlier that PCR tests would be required for all overseas arrivals.
Arrivals from 10 new red list countries will need to quarantine for 10 days.
MPs are due to vote on confirming the measures after they come into force.
The government has stopped short of extending vaccine passports in England and issuing advice to work from home, which are part of its Plan B – a contingency plan if intervention on Covid is needed to protect the NHS.
Mr Javid told Sky News the actions being taken were “proportionate and balanced”, and he hoped they could be lifted “within weeks”.
He told the Trevor Phillips on Sunday programme it would be “irresponsible” to make guarantees about Christmas, but said people should continue with their plans.
“I think it’s going to be a great Christmas,” he said.
The health secretary said tighter rules on testing for overseas arrivals would be implemented “as soon as possible” with the agreement of the UK’s four nations.
But Mr Javid said the country was “nowhere near” reintroducing measures such as working from home or social distancing, arguing that they carry a “heavy price” economically, socially and in terms of mental health.
He added that he was expecting the government’s vaccines advisers to advise him “imminently” on broadening the booster programme to younger age groups.
At a Downing Street news conference on Saturday, the prime minister called the new measures temporary and precautionary – and said they would be reviewed in three weeks, just before most schools break up for the Christmas holidays.
Labour has called for full implementation of Plan B and for improved sick pay to encourage self-isolation.
Boris Johnson announced the restrictions after it was confirmed that two Omicron cases had been detected in Brentwood, Essex, and Nottingham. Officials said the cases were linked and connected to travel in southern Africa, where the new variant was first identified.
Mr Johnson said: “We need to slow down the spread of this variant here in the UK, because measures at the border can only ever minimise and delay the arrival of a new variant rather than stop it all together.”
The government’s response is to test everyone coming in to the UK, isolate all Omicron contacts, ramp up boosting and bring back compulsory face masks in some public places.
Let’s be clear – that will not stop more Omicron cases arriving or circulating. It’s already arrived. If a virus is good at spreading then eventually it will slip through.
And it has the potential to spread here too. Cases of Covid have been climbing except for a lull over the October half term.
They are averaging at more than 40,000 a day and the R number is just above the crucial threshold of one. If Omicron can combine faster transmission with some ability to evade immunity then it too could spread.
All the measures can do is buy time, but for what? Science and boosters.
Under the plans:
- Everyone entering the UK (other than those coming from the Common Travel Area that covers the Channel Islands and Ireland) will have to take a PCR test by the end of the second day after their arrival and self-isolate until they receive a negative result
- All contacts of suspected Omicron cases must self-isolate, regardless of whether or not they are fully vaccinated
- Face coverings will be made compulsory in shops and on public transport – but pubs and restaurants are exempt
- The health secretary is to ask advisers to consider rapidly extending boosters, including reducing the gap between the second dose of the vaccine and the booster
In Scotland, Wales and Northern Ireland, face coverings are already mandatory on public transport and many indoor areas.
But retail and health workers said the rules on face masks should never have been relaxed, with shopworkers’ union Usdaw accusing ministers of “flip-flopping on basic and sensible Covid measures”.
“Retail staff working with the public every day are deeply worried about catching Covid-19 and the arrival of the Omicron variant is a further concern,” said Usdaw’s Paddy Lillis.
Carol Popplestone, chairwoman of the Royal College of Nursing, said face coverings were “something we have already called for and it should not have been a new variant that forced the prime minister to act”.
One change has already been implemented. Ten countries – South Africa, Namibia, Zimbabwe, Botswana, Lesotho, Eswatini, Angola, Mozambique, Malawi and Zambia – are now on the UK’s travel red list. That was applied from 04:00 GMT, meaning that until further notice any British or Irish residents arriving in the UK after recently visiting any of those countries will have to quarantine in an approved hotel for 10 days.
Residents from the countries themselves will not be allowed into the UK until the red list status changes.
The average number of daily confirmed Covid cases in the UK began rising again in early November. A further 39,567 confirmed cases were announced on Saturday.
This is a moment the government had wanted to avoid.
We’ve got used to restrictions in England being lifted. But for the first time in months, they’re now being re-imposed in response to the new variant.
And these restrictions could have a significant impact.
For example, anyone who goes on holiday will now need to pay for a PCR test and self-isolate until they get a negative result. If Omicron spreads quickly, there could be a lot of people forced to self-isolate for 10 days as close contacts.
But the government hasn’t gone for its full plan B. Masks won’t be mandatory in hospitality settings in England like they are in Scotland.
People aren’t being told to work from home – and there still aren’t plans for vaccine passports.
But it’s a sign of the uncertainty and concern in Whitehall that Boris Johnson felt he had to announce these measures.