The government has performed a U-turn just three hours after announcing that Boris Johnson and Rishi Sunak would not have to self-isolate – despite both having come into contact with Sajid Javid, who has tested positive for COVID-19.
The prime minister will now isolate at Chequers after being "pinged" by the NHS Test and Trace app, a Downing Street spokesperson said.
Johnson and chancellor Sunak had previously announced that they would take part in a pilot daily testing programme that would allow them to continue working without quarantining.
Sunak tweeted his reasoning for the U-turn: "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.
"To that end I'll be self-isolating as normal and not taking part in the pilot."
On Saturday, Javid said he had tested positive for coronavirus, but that that his symptoms were mild and he was thankful to have had two vaccine doses.
Sunday's rapid turnaround came after anger erupted when the government announced on Sunday morning that both Johnson and Sunak would be taking part in the daily contact testing pilot.
The criticism came as thousands of people are being forced to miss work after being 'pinged'.
Meanwhile, businesses have been pressing for the app to be overhauled and made less sensitive amid concerns that staff shortages mean firms cannot operate effectively.
Johnson's spokesman said on Friday that the app was "working as it is designed to do" amid reports that there are no plans to change its sensitivity.
Shadow health secretary Jonathan Ashworth was among the many people who spoke out against the PM and chancellor taking part in the pilot.
He said many people across the UK would be dismayed by the "special, exclusive rule".
"There will be parents across the country who have struggled this year when their children have been sent home because they were in a bubble and had to self-isolate," he told Sky News.
"There will be workers across the country that have to isolate because they’ve been pinged, including in public services, including the NHS.
"For many of them, waking up this morning to hear that there is a special rule, an exclusive rule, for Boris Johnson and Rishi Sunak – they will be saying that this looks like one rule for them and something else for the rest of us."
He added: "Nobody understands how you can get access to this special treatment or VIP lane where you don’t have to isolate yourself."
Green Party co-leader Jonathan Bartley said "anger doesn’t begin to cover it" as he reacted to the announcement.
He wrote on Twitter: "Hundreds of thousands of young people, including my children, had their education and lives repeatedly turned upside down again and again after dutifully and responsibly isolating. And now this. Anger doesn’t begin to cover it."
Liberal Democrat leader Sir Ed Davey said: "It is one rule for them and another rule for everyone else.
"How about the school teachers, transport workers and health workers getting a chance to be part of this test pilot or is it only for the privileged few?
"People have stuck to the rules and done the right thing, Boris Johnson is taking them for granted."
Watch: No plans to change sensitivity of NHS contact tracing app
Dr Ellie Cannon, an NHS GP and Mail on Sunday columnist, also criticised the government, saying: "There have been low points in this pandemic. And then there have been lower points."
She tweeted: "Perhaps the lowest point for me was watching the funeral prayers of an acquaintance who died in particularly difficult circumstances...
"Their own child, mourning their parent’s sudden death, was not allowed in the place of worship with family because they were contact isolating from school.
"No-one found special pilot schemes for them."
It comes after Johnson was warned that millions of people could be pinged by the NHS COVID app or ordered to self-isolate by Test and Trace over the summer, with infections expected to hit around 100,000 a day.
This prompted staff shortage concerns in several industries.
The British Meat Processors Association said companies may be forced to shut down production lines if more workers are forced to isolate.
Car-makers Rolls-Royce and Nissan also warned that their manufacturing plants faced major disruption due to the number of people being told to self-isolate by the app.
More than half a million alerts were sent out in the week to 7 July, a 46% rise on the previous week and the highest number on record.
The rise in the number of pings sent out since restrictions were eased in May indicates they may rise even faster once more restrictions are lifted.
Being told to self-isolate by the app is currently not legally enforceable, unlike if you are told to self-isolate by an employee of NHS Track and Trace.
Despite this, all official guidance does encourage people to follow the rules and many people do so.
Watch: Concerns mount over 'pingdemic' as Test and Trace app wreaks havoc