LONDON — British Prime Minister Boris Johnson was admitted to hospital for tests on Sunday (April 5) after suffering persistent coronavirus symptoms 10 days after testing positive for the virus, though Downing Street said he remained in charge of the government.

Mr Johnson, who was isolating in Downing Street after testing positive last month, still had a high temperature and so his doctors felt he should go to hospital for tests in what the government said was a "precautionary step".

"On the advice of his doctor, the prime minister has tonight been admitted to hospital for tests," his Downing Street office said in a statement. Mr Johnson is expected to stay overnight.

"This is a precautionary step, as the prime minister continues to have persistent symptoms of coronavirus ten days after testing positive for the virus," the statement added.

News of his hospitalisation came only after an hour after Queen Elizabeth delivered a rallying call to the British public saying they would overcome the coronavirus outbreak if they stayed resolute.

Mr Johnson, 55, on March 27 became the first leader of a major power to announce that he had tested positive. He went into isolation at an apartment in Downing Street and said on Friday he was staying there as he still had a high temperature.

Downing Street underscored that this was not an emergency admission and that Johnson remains in charge of the government. Foreign Secretary Dominic Raab will chair the government's emergency Covid-19 meeting on Monday, a source said.

With only an unwieldy collection of sometimes ancient and contradictory precedents to go by, there is no simple, formally-enshrined "Plan B" or succession scenario if the prime minister is incapacitated.

The pound briefly fell 0.4 per cent vs the US dollar to US$1.2215 before trimming some losses to trade at US$1.2230, down 0.3 per cent.

Queen Elizabeth has been informed of Mr Johnson's admission to hospital, Buckingham Palace said. It made no further comment.

"Wishing the prime minister well and a speedy recovery," Mr Keir Starmer, the newly elected leader of the opposition Labour Party, said.

CORONAVIRUS IN THE UK

Mr Johnson, the face of the 2016 Brexit campaign, won a resounding election victory in December before leading the United Kingdom out of the European Union on Jan 31.

But he has faced criticism in the United Kingdom for initially approving a much more modest response to the novel coronavirus outbreak than other major European leaders.

He then changed tack when scientific projections showed a quarter of a million people could die in the United Kingdom.

Mr Johnson effectively shuttered the world's fifth-largest economy, advising people to stay at home and the elderly or infirm to isolate themselves for weeks.

But the virus penetrated the British government.

Mr Johnson and his health minister tested positive last month and his chief medical adviser also self isolated. Mr Johnson's pregnant 32-year-old fiancee, Ms Carrie Symonds, also had symptoms but said on Saturday she was feeling better.

From an apartment above Number 11 Downing Street, and with food brought to his door, Mr Johnson continued to lead the government's response and chaired meetings via video conference.

"Although I'm feeling better and I've done my seven days of isolation, alas I still have one of the symptoms, a minor symptom, I still have a temperature," a weary-looking Mr Johnson, sitting in a chair with his shirt open at the neck, said in a Twitter video message on Friday.

He was taken to an unidentified hospital on Sunday evening.

Downing Street refused to say what tests Mr Johnson was to have in hospital.

Experts said the most likely tests for a person of the prime minister's age with Covid-19 symptoms after 10 days would be to assess oxygen levels and an electrocardiogram check of his heart.

"Doctors will be monitoring important vital signs such as oxygen saturations," said Dr Rupert Beale, Group Leader, Cell Biology of Infection Laboratory at the Francis Crick Institute.

"They will also check blood tests to see what the immune response to the virus looks like, and to assess liver and kidney function."

Other tests could include a CT scan of the chest to get an accurate picture of the lungs.

"The prime minister thanks NHS staff for all of their incredible hard work and urges the public to continue to follow the government's advice to stay at home, protect the NHS and save lives," Downing Street said.

The United Kingdom's death toll from the coronavirus rose by 621 to 4,934 at 1600 GMT on April 4, the health ministry said on Sunday. As of 0800 GMT, a total of 195,524 people had been tested of which 47,806 tested positive. REUTERS