10 Downing Street initially said they wouldn't have to isolate as they were taking part in a pilot scheme which requires them to test daily, according to BBC.

However, the opposition criticised this and said that such a decision suggested  there was "one rule for them and another for the rest of us", the report added.

Johnson said he had briefly considered taking part in the scheme.

Britain is set to lift almost all Covid-19 restrictions from Monday, including limits on gatherings, night clubs and other public places, but isolation rules will continue.

According to BBC, speaking in a video on Twitter after the U-turn, Mr Johnson said: "We did look briefly at the idea of us taking part in the pilot scheme, which allows people to test daily, but I think it's far more important that everybody sticks to the same rules and that's why I'm going to be self-isolating until Monday 26 July.

"I know how frustrating it all is, but I really do urge everybody to stick with the programme and take the appropriate course of action when you're asked to do so by NHS Test and Trace."

The prime minister also defended the lifting of covid-induced restrictions even as fresh cases, deaths and hospitalisations continue to rise. He, however, urged people to maintain caution.

He said: "We've got to remember that this virus is sadly still out there. Cases are rising. We can see the extreme contagiousness of the Delta variant, but we have this immense consolation and satisfaction that there is no doubt at all that the vaccine programme has very severely weakened the link between infection and hospitalisation and between infection and serious illness and death."

The BBC report said the prime minister will now work from Chequers, his official countryside retreat, where he was when the health secretary received his positive test result.

Mr Sunak said on Twitter: "Whilst the test and trace pilot is fairly restrictive, allowing only essential government business, I recognise that even the sense that the rules aren't the same for everyone is wrong."

Britain's health secretary Sajid Javid tested positive on Saturday morning after a meeting at Downing Street the day before, and both Johnson and Sunak were contacted by NHS Test and Trace, the BBC report stated.