British Prime Minister Boris Johnson was moved to an intensive care unit on Monday after his coronavirus symptoms worsened, but his Downing Street office said he was still conscious.
Britain has no formal succession plan should the prime minister become incapacitated, but Johnson, 55, asked Foreign Secretary Dominic Raab to deputise for him.
Mr. Johnson was admitted to hospital on Sunday night and had been undergoing tests after suffering persistent coronavirus symptoms, including a high temperature, for more than 10 days.
Downing Street had said he was in good spirits and still in charge, though at about 1800 GMT he was moved to an intensive care unit - where the most serious cases are treated - at St Thomas' hospital, across the River Thames from the Houses of Parliament in central London.
Over the course of this afternoon, the condition of the Prime Minister has worsened and, on the advice of his medical team, he has been moved to the Intensive Care Unit at the hospital, a spokesman for his office said.
The PM has asked Foreign Secretary Dominic Raab, who is the First Secretary of State, to deputise for him where necessary, Downing Street said. The PM remains conscious at this time.
Downing Street said he had been moved to the intensive care unit as a precaution should he require ventilation to aid his recovery.
Mr. Johnson, 55, tested positive for the virus on March 26.
His spokesman had earlier urged caution about media reports that Johnson was receiving oxygen treatment, but refused to answer directly after being asked whether he had pneumonia.
The Times newspaper and ITV correspondent Robert Peston said Johnson had received oxygen.
Mr. Raab, 46, chaired the government's emergency COVID-19 meeting on Monday.
Carrie Symonds has not been tested
Mr. Johnson's pregnant partner, Carrie Symonds, moved out of Downing Street after some staff fell ill. But she said on Saturday she had just spent a week in bed with symptoms, although she has not been tested.
Mr. Johnson's spokesman would not confirm a report in The Times newspaper reported that the prime minister had been given oxygen treatment.
Doctors will be monitoring important vital signs such as oxygen saturations, said Rupert Beale, group leader at the cell biology of infection laboratory at the Francis Crick Institute.
He said they would also check Mr. Johnson's blood to see what the immune response to the virus looks like, and to assess liver and kidney function, and may also perform an electrocardiogram to check the heart.
Below are some immediate comments from health experts:
- Derek Hill, a professor of medical imaging at University College London (UCL): There is no doubt this turn of events means Boris Johnson is extremely sick. One of the features of COVID-19 in all countries seems to be that many more men become seriously ill than women - especially in the over 40 age group. Also we know that people under about 60 seem to have a higher chance of making a recovery from critical illness with COVID-19 than older people.
- Linda Bauld, a professor of public health at the University of Edinburgh: The admission of the Prime Minister to intensive care is of huge concern and illustrates just how indiscriminate this virus is. Anyone anywhere, including the most privileged in our society, can be affected and can become seriously ill. It is imperative now, more than ever that the rest of us comply with government guidelines to stay at home and not put others at risk.
Below is reaction to the news:
KEIR STARMER, LEADER OF THE MAIN OPPOSITION LABOUR PARTY: Terribly sad news. All the country's thoughts are with the Prime Minister and his family during this incredibly difficult time.
LONDON MAYOR SADIQ KHAN: Praying for the Prime Minister's swift recovery tonight. @GSTTnhs (Guy's and St Thomas' NHS) has some of the finest medical staff in the world, and he couldn't be in safer hands.
LIZ TRUSS, BRITISH TRADE MINISTER: My thoughts are with the Prime Minister and his family as he is moved into intensive care this evening. Wishing him a speedy recovery.
ED DAVEY, LEADER OF THE OPPOSITION LIBERAL DEMOCRATS: Thoughts are with Boris Johnson & his family at this latest news - best wishes for an early full recovery. Thanks to all NHS & social care staff looking after anyone who is ill tonight. Together we must beat #Covid_19
IAN BLACKFORD, WESTMINSTER LEADER OF THE SCOTTISH NATIONAL PARTY: So sorry to hear that @BorisJohnson is now in intensive care. This is very worrying news. Thoughts and prayers with Boris (his fianc_e) @carriesymonds and all their family. This is such a terrible virus that we all must take seriously. Get well soon Boris, look forward to you being back.
RISHI SUNAK, FINANCE MINISTER: My thoughts tonight are with Boris Johnson and (his fiancee) Carrie Symonds. I know he'll be getting the best care possible and will come out of this even stronger.
LINDSAY HOYLE, SPEAKER OF THE HOUSE OF COMMONS: This is terrible news. I know the thoughts and prayers of everyone across the House are with the Prime Minister and his family right now. We all wish him a speedy recovery.
PRITI PATEL, INTERIOR MINISTER: My love & thoughts are with Boris Johnson, Carrie Symonds & the Prime Minister's family. Folded hands (emoji) for you & thinking of you.