Boris Johnson and Chancellor Rishi Sunak are both self-isolating for 10 days after being told to quarantine by NHS Test and Trace.
Here is a look at the timeline leading up to their alerts.
– Why are the Prime Minister and Chancellor having to self-isolate?
Both were deemed by NHS Test and Trace to have come into close contact with Health Secretary Sajid Javid, who tested positive for coronavirus over the weekend.
– When did the Health Secretary find out he had the virus?
Mr Javid posted a video on social media on Saturday confirming he was showing mild symptoms and had tested positive after using a lateral flow test – a test usually reserved for those not displaying symptoms.
The Cabinet minister, who is fully vaccinated, said he took a PCR test to confirm the result, with the confirmation of his positive status coming back on Saturday evening.
– When did the Prime Minister last meet the Health Secretary?
Downing Street said the men last met on Friday lunchtime at No 10, but that it was not known if that was when the “close contact” was judged to have happened, as they, along with the Chancellor, held regular meetings last week.
– Where and when was Mr Johnson told he needed to self-isolate?
He was at his official country residence in Chequers in Buckinghamshire, although the Prime Minister’s official spokesman said he did not know “specifically” when Mr Johnson discovered Mr Javid had tested positive, or when he was contacted by the NHS tracing operation.
– Was Mr Johnson permitted to travel to Chequers if he had been in contact with Mr Javid?
Mr Johnson’s spokesman said he followed the “correct process” in terms of self-isolating after being contacted by NHS Test and Trace.
“My understanding on this is that the Prime Minister travelled to Chequers on Friday,” he told reporters.
“The Health Secretary took his test on Saturday, so the correct process has been followed.
“Once contacted by NHS Test and Trace over the weekend, he has isolated and has not travelled subsequently because he did not want to travel across the country.”
– Is that settled then?
Possibly, but there seemed to be confusion even in No 10 about Mr Johnson’s movements.
The spokesman gave different answers when asked about when the Prime Minister travelled from Downing Street to Chequers, first telling reporters it was at the “start of the weekend” and then Friday morning.
After it was pointed out that Mr Javid was spotted leaving Downing Street at about 2pm on Friday, following his meeting with the Prime Minister, Mr Johnson’s spokesman said it was actually at 3pm that he left for Buckinghamshire.
– If the Government is following social distancing, how come ministers have been told to self-isolate?
The Prime Minister’s spokesman, asked whether ministers had failed to adhere to social distancing rules in order to have been alerted to self-isolate, said ministers had been “taking the requisite precautions”.
“It is down to NHS Test and Trace to decide what constitutes a close contact – there are broad guidelines but they may take other things into account,” he continued.
“The Chancellor, Prime Minister and Health Secretary, as you would expect, have a number of meetings which can last more than an hour certainly, so obviously Test and Trace have taken that decision, but it is not for me to comment on how they came to that decision.”
– How is the Prime Minister?
No 10 says he has tested negative for the virus and is showing no symptoms.
Mr Sunak, meanwhile, is self-isolating at his flat above 10 Downing Street.