Boris Johnson has been contacted by NHS Test and Trace as a contact of someone who has tested positive for Covid-19 but will not be self-isolating, Downing Street has said.
Instead, the Prime Minister will be taking part in a daily contact testing pilot which allows him to continue to work from Downing Street.
The announcement follows the disclosure on Saturday that Health Secretary Sajid Javid had been confirmed as testing positive for the virus.
The Prime Minister is reported to have had a lengthy meeting with Mr Javid at No 10 on Friday.
Chancellor Rishi Sunak has also been contacted by Test and Trace and will also be taking part in the contact testing pilot.
A No 10 spokesman said: “They will be conducting only essential government business during this period.”
There will be relief in Downing Street that Mr Johnson will not be confined to home on so-called “freedom day” on Monday when most statutory lockdown restrictions end in England.
However, the disclosure that the Prime Minister and Chancellor have avoided the requirement to quarantine is likely to anger thousands of people being forced to miss work after being “pinged” by the NHS Covid app.
Businesses have been pressing for the app to be overhauled and made less sensitive amid concerns that staff shortages mean they cannot operate effectively.
London Underground became the latest to succumb on Saturday when the Metropolitan Line was forced to close because of a lack of control room staff.
While most Covid restrictions lift in England on Monday the rules on self-isolating for contacts of people who test positive are not eased until August 16.
Then people who are double-jabbed will be able to take tests rather than quarantine at home.
Communities Secretary Robert Jenrick said members of the public who are pinged should still self-isolate.
He said the test-and-release pilot being used by Mr Johnson and Mr Sunak was being trialled by about 20 public sector organisations including Border Force and Transport for London.
He said the two minsters would be tested at a special testing centre which has been set up in Downing Street.
“It is correct that the Cabinet Office and Downing Street are part of the pilot. I am not aware that other (government) departments are,” Mr Jenrick told Sky News.
“It means that you can be tested every day in specialist asymptomatic testing centres such at the one that has been set up in Downing Street.
“It means that the Chancellor and the Prime Minister will be able to conduct the most essential Government meetings but the rest of their time will have to be spent isolating and not meeting up with family or friends or socialising. So it is relatively restrictive.
“I entirely appreciate that this isn’t available yet to wider members of the public and the frustration that they might feel listening to this.
“Other members of the public who are pinged will have to self-isolate in the usual way and that is a really important part of our plan to keep Covid under control.”