Boris Johnson has been admitted to hospital for tests as his coronavirus symptoms persist, Downing Street has said.
He has been in self-isolation since he tested positive for Covid-19.
“This is a precautionary step, as the prime minister continues to have persistent symptoms of coronavirus 10 days after testing positive for the virus.”
In a statement, a Downing Street spokeswoman said: "On the advice of his doctor, the prime minister has tonight been admitted to hospital for tests.
She added: "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."
Mr Johnson has worked from home since it was announced that he had tested positive for coronavirus on 27 March.
He was last seen in public applauding the NHS and other key workers from his flat in Downing Street on Thursday evening, and chaired a coronavirus meeting via video-link on Friday morning.
Mr Johnson remains in charge of the government, but the foreign secretary is expected to chair a coronavirus meeting on Monday morning.