After news broke on Sunday morning that both Boris Johnson and Rishi Sunak had been contacted by Test and Trace, having coming into contact with somebody who had Covid, Number 10 initially said the pair were partially exempt from having to self-isolate.
A government statement cited a pilot scheme that allowed contacts to continue with essential activities, like work.
After furious backlash, Number 10 U-turned on their position and said both the PM and Chancellor would be fully self-isolating.
So what is the scheme, who is eligible, and when will you be able to use it?
What is the new scheme?
The workplace pilot scheme will assess the effectiveness of daily contact tracing for those who have been in contact with people testing positive for coronavirus.
Rather than self-isolating fully, close contacts will be contacted by phone and sent seven days’ worth of lateral flow tests to perform each morning.
Those who develop no symptoms and also test negative will be exempt from self-isolation on that day and can leave their homes to carry out essential activities.
The study is being led by Public Health England and NHS Test and Trace, according to the Department of Health and Social Care (DHSC).
It began in December 2020 and findings are due to published later this summer.
Who is involved?
It's unclear when the businesses cited by Number 10 began the trial.
A release on the government website details a daily contact tracing study involving 40,000 people but does not mention specific employers.
When Number 10 announced both politicians were involved in the trial on Sunday, they said Downing Street was one of 20 organisations involved in the pilot.
'This is a well known and longstanding pilot that's being conducted across a range of public sector organisations' says Robert Jenrick
Communities Secretary Robert Jenrick told ITV News it was a "well known and longstanding pilot" with Network Rail, TFL, Heathrow and Border Force all involved.
But a TfL spokesperson said the company had received no official notification to say they were a part of such a trial - indeed one of London's Underground lines was closed on Saturday due to staff shortages as a result of workers self-isolating.
A TfL spokesperson said "The current Test and Trace rules on self-isolation have led to vital control room staff being unable to come to work, causing disruption on some Tube lines.
"The government has indicated that we could be part of a trial whereby daily tests would replace the need for self-isolation. We are still waiting for formal notification from them that we are part of this trial so that we can brief our trade unions and put this into effect."
On the other hand, Heathrow airport confirmed on Sunday they were participating in the scheme.
A Heathrow spokesperson said: “This important tool enables us to manage resourcing levels and keep the UK’s largest port open.
"However, the pilot is due to expire at the end of July. We have written to ministers urging them to extend it so that our colleagues can continue to safely do their jobs supporting the UK’s economic recovery even as infections increase."
What was the reaction to the initial announcement?
After initially stating the PM and Mr Sunak would not be self-isolating (before the U-turn) Downing Street was accused of making "one rule for them and another for the rest of us".
Labour said the government needed "to be seen to be following the rules, because confidence is everything in a pandemic".
Co-leader of the Green Party Jonathan Bartley said "anger doesn’t begin to cover it" after the initial announcement, saying people had had their "education and lives repeatedly turned upside down again and again after dutifully and responsibly isolating".
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What has Number 10 said?
In the first statement, announcing the pair would not be self-isolating, Downing Street explained: "They will be participating in the daily contact testing pilot to allow them to continue to work from Downing Street. "They will be conducting only essential government business during this period."
A Downing Street spokesperson later said: "The Prime Minister has been contacted by NHS Test and Trace to say he is a contact of someone with Covid.
"He was at Chequers when contacted by Test and Trace and will remain there to isolate. He will not be taking part in the testing pilot.
"He will continue to conduct meetings with ministers remotely. The Chancellor has also been contacted and will also isolate as required and will not be taking part in the pilot."
Can anyone apply to be involved?
The DHSC said no further organisations would be invited to take part in the scheme until further data from the preliminary trials was returned.
What is the current situation for everybody else?
Currently, anybody who has been notified through NHS Test and Trace as a contact of someone who has tested positive for coronavirus must self-isolate for 10 days without exemption.