The UK prime minister Boris Johnson and health secretary Matt Hancock have tested positive for coronavirus.
Both are exhibiting mild symptoms and are continuing to work while self-isolating.
Meanwhile, the Department of Health announced that the number of people in the UK who had died after contracting coronavirus had jumped to 759 as of 5 pm on Thursday, from 578 the previous day.
As of 9 am on Friday, 14,579 people in the UK had tested positive for the disease.
Downing Street said Mr Johnson had a temperature and a cough and would self-isolate for the next seven days.
Officials insisted that he would continue to lead the government’s response to the crisis.
Mr Johnson posted a video on Twitter in which he said the public should “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 fightback against coronavirus”.
His official spokesman said the prime minister “will do the same things” but they “will be done exclusively via teleconferencing on his part”.
Dominic Raab, the foreign secretary and first secretary of state, would stand in for Mr Johnson if he became incapacitated.
After experiencing mild symptoms on Thursday, Mr Johnson was tested for coronavirus by National Health Service staff on the personal advice of England’s chief medical officer, Chris Whitty.
He received the results of the test at midnight.