Boris Johnson has urged England to "stick with the programme" ahead of Freedom Day, as he self-isolates at Chequers after being "pinged" by the NHS Covid app.
After reversing course and announcing that he would isolate following contact with health secretary Sajid Javid, who has tested positive for Covid-19, the Prime Minister said "it's far more important that everybody sticks to the same rules".
Johnson and chancellor Rishi Sunak had originally planned to avoid self-isolation through a daily contact testing pilot but abandoned those plans following a furious political backlash.
In a video on Twitter, he said that he will be self-isolating until July 26.
"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," he added.
Johnson is proceeding with the full re-opening of the economy on July 19 despite a fresh surge of cases fuelled by the highly transmissible delta variant. New infections are running at their highest level since January.
The UK has recorded 48,161 new cases and 25 further coronavirus-related deaths in the last 24 hours.
It comes as all UK adults have now been offered a first Covid-19 vaccine dose.
Labour leader Sir Keir Starmer described the Government's plans to lift "all restrictions" from Monday as a "mistake" and the "wrong thing to do".
He said: "I've said consistently that lifting all restrictions in one go tomorrow is a mistake, it's reckless.
"We can already see that the infection rates are going through the roof, we know what's going to happen with hundreds of thousands of people being asked to self isolate.
"The Prime Minister is essentially putting the whole nation into a car, pressing the accelerator and taking the seatbelt off."
Earlier, Starmer accused the Government of "double standards" and being "contemptuous of the British public" over the Prime Minister's now abandoned plans to avoid quarantine after being contacted by NHS Test and Trace.
Speaking to the media in north London, Starmer said: "Yet again, it's double standards from the Government.
"The Prime Minister is causing utter chaos with his reckless decision making and that means infection rates are going through the roof, hundreds of thousands of people are having to self-isolate, and they're doing the right thing.
"What happens when the rules apply to the Prime Minister? He tries to wriggle out of them and to pretend that he's on some pilot scheme that exempts him.
"So I'm afraid yet again, we see it's one rule for them and another rule for everybody else."
Starmer added of the Prime Minister: "The only reason that he's u-turned on this is because he's been busted.
"It's like bank robbers who've got caught and now they're offering the money back.
"One rule for them, another rule for everybody else. It's contemptuous of the British public."
He said Johnson's "reckless decisions" were causing "utter chaos".