England is building temporary hospitals to help cope with rising coronavirus cases, as Prime Minister Boris Johnson on Friday issued a stark warning to those not fully vaccinated.
The new "surge hubs" would deal with a potential overspill of inpatients as surging virus cases put the country's health service on a "war footing", according to officials.
Fuelled by the highly contagious Omicron variant, daily cases have ballooned, standing at more than 189,000 on Thursday.
While stressing the success of the booster roll out, Johnson said he wanted to "speak directly to all those who have yet to get fully vaccinated. The people who think the disease can't hurt them".
"Look at the people going into hospital now, that could be you. Look at the intensive care units and the miserable, needless suffering of those who did not get their booster, that could be you," he said.
NHS England said it would provide extra beds in structures in the grounds of eight hospitals in cities including London, Bristol and Leeds from this week, with each designed to house around 100 extra patients.
Outside St George's Hospital in Tooting in south London, workers were already putting up a metal framework to support the roof of a new unit, AFP journalists saw on Thursday.
"Given the high level of Covid-19 infections and increasing hospital admissions, the NHS is now on a war footing," National Medical Director Stephen Powis said.
He added that he hoped "we never to have to use these new hubs".
The extra beds are designed for patients who are recovering from illnesses, including those who no longer have Covid, to free up space and staff in the adjacent hospitals to treat large numbers of virus cases.
The UK has been one of Europe's worst hit countries with a death toll of over 148,000.
- 'Super-surge beds' -
The government opened large "Nightingale" field hospitals in venues such as exhibition centres during the first wave of the virus. The facilities named after nursing pioneer Florence Nightingale were not widely used and staffing was a problem due to their vast size.
This time, the plan is to make available as many as 4,000 "super-surge beds", in some cases using existing hospital facilities such as gyms or education centres.
Medics warned of rising staff shortages due to people off sick with the virus or self-isolating.
England is the exception among UK nations in not imposing extra virus curbs for the festive period, while Wales, Scotland and Northern Ireland have imposed limits on how many people can socialise together and closed nightclubs.
Johnson has said that the high booster takeup rate in England plus evidence that Omicron is milder have allowed the country to avoid more restrictions.
He has urged people to get tested before attending New Year's events and be "sensible".
The numbers of people testing positive or in self-isolation is hitting sectors including transport.
The Southern rail company announced Thursday it will not run trains from London's Victoria station, one of the UK's busiest, until January 10 due to "coronavirus isolation and sickness".
Agence France-Presse