Britain on Friday opened a new 4,000-bed temporary hospital to treat the most seriously ill coronavirus patients, as day-on-day deaths surged to a new record and royal officials said Queen Elizabeth II would make a rare crisis address to the nation.

Heir to the throne Prince Charles opened the state-run National Health Service (NHS) Nightingale Hospital, which has been built at London's ExCeL conference venue in just nine days.

The 71-year-old prince officially launched the facility via videolink from Scotland, where he has been in self-isolation after testing positive for COVID-19.

Prime Minister Boris Johnson, 55, who has also tested positive, said he would remain at home in quarantine because he still had a temperature.

The hospital has been built in just nine days
The hospital has been built in just nine days AFP / Tolga AKMEN

Charles and Johnson are among 38,168 confirmed coronavirus cases across Britain. Numbers increased by 4,450 in the 24 hours to 0800 GMT on Friday, according to the health ministry.

There was also a third consecutive day of record deaths from confirmed hospital cases -- 684 -- taking the overall toll to 3,605 as of 1600 GMT on Thursday.

Two NHS nurses and two healthcare assistants were among the fatalities in the last 24 hours, Health Secretary Matt Hancock, who has also tested positive for COVID-19, told a daily briefing.

Chief Nursing Officer for England Ruth May added: "I worry that there's going to be more. I want to honour them today and recognise their service."

The announcement of the new figures coincided with news the queen would make a rare special broadcast to Britain and the Commonwealth at 1900 GMT on Sunday.

Britain's Health Secretary Matt Hancock said the hospital will initially take in 500 people in the coming days
Britain's Health Secretary Matt Hancock said the hospital will initially take in 500 people in the coming days AFP / Tolga AKMEN

The queen, 93, has made only three other special addresses in her 68-year reign: after her mother's death in 2002; before Diana, Princess of Wales' funeral in 1997; and during the first Gulf War in 1991.

She has been with her 98-year-old husband Prince Philip at Windsor, west of London, since March 19 as a precaution but palace officials have said the couple were in "good health".

The NHS Nightingale Hospital is named after the trailblazing 19th-century nurse Florence Nightingale, who is seen as one of the founders of modern nursing.

A new 4,000-bed temporary hospital is inaugurated in London
A new 4,000-bed temporary hospital is inaugurated in London UK POOL /

Charles paid tribute to everyone involved its construction, calling it "quite frankly incredible" to have transformed the giant exhibition centre into a critical care facility so quickly.

"I was one of the lucky ones to have COVID-19 relatively mildly," he said. "But for some, it will be a much harder journey.

"I am therefore so relieved that everyone can now have the reassurance that they will receive all the necessary technical care they may need, and every chance to return to a normal life.

"In this dark time, this place will place will be a shining light," he said, but added that he hoped it would not required for long.

The hospital will initially take 500 people in the coming days, said Health Secretary Matt Hancock, who has also tested positive for COVID-19.

It will take intensive care patients with COVID-19 from other London hospitals, which have seen the highest numbers of cases across Britain.

But they said there were more than 2,000 critical care beds free, even before the opening of new field hospitals.

The NHS Nightingale Hospital London -- one of six being set up around the country -- is the size of 10 district general hospitals, and has more than 80 wards, each containing 42 beds.

When fully operational it will require more than 16,000 staff to run it.

Britons have been told to stay at home wherever possible and non-essential shops and services have been shut since March 23, as part a nationwide lockdown designed to stem the spread of coronavirus.

Health officials say will take weeks to have an effect but the government said it was dependent on people maintaining social distancing.

Hancock said it was not a guideline but an "instruction".