Prime Minister Boris Johnson has tested positive for coronavirus.
Mr Johnson said he had developed mild symptoms over the past 24 hours, including a temperature and cough.
He is self-isolating in Downing Street but said he will “continue to lead the government’s response via video-conference as we fight this virus”.
It comes as another 181 people died with the virus in a day, latest government figures showed.
It takes the total number of UK deaths to 759, with 14,579 confirmed cases.
Following Mr Johnson’s announcement, Health Secretary Matt Hancock also said he had tested positive for the virus.
Mr Hancock said his symptoms were also mild and he was working from home and self-isolating.
Mr Johnson was last seen on Thursday night, clapping outside No 10 as part of a nationwide gesture to thank NHS staff and carers.
He is thought to be the first world leader to announce they have the virus.
In a video on his Twitter account, Mr Johnson, 55, said: “I’m working from home and self-isolating and that’s entirely the right thing to do.
“But, be in no doubt that I can continue thanks to the wizardry of modern technology to communicate with all my top team to lead the national fight-back against coronavirus.
“I want to thank everybody involved and, of course, our amazing NHS staff”