Mr Johnson must now self-isolate for two weeks but still wants to address the public and lead the fight against the coronavirus pandemic.
A No10 spokesman said: “The Prime Minister has today been notified by NHS Test and Trace that he is required to self-isolate as a contact of someone who has tested positive for COVID-19.
“The Prime Minister will follow the rules and is self-isolating. He will carry on working from Downing Street, including on leading the Government’s response to the coronavirus pandemic.
“The PM is well and does not have any symptoms of COVID-19.”
The PM met with a small group of MPs for a breakfast meeting in Downing Street on Thursday morning including Lee Anderson, the MP for Ashfield. The pair were pictured together standing less than two metres apart and not wearing masks.
Mr Anderson subsequently developed symptoms for COVID-19 and has now tested positive along with his wife Sinead who has cystic fibrosis.
He wrote on Facebook: “On Friday I lost my sense of taste at the same time my wife had a bad headache.
“I had no cough, no fever and felt well. We both had a test on Saturday and the result came in Sunday morning. My wife and I both tested positive. I feel absolutely fine and my biggest concern is my wife who is in the shielded group.
“But we are both feeling good.”
Dominic Raab was left in charge of running much of the government when the prime minister was hospitalised by Covid-19 – but Boris Johnson never formally relinquished control.
Boris Johnson: This winter is not going to be easy
- Boris Johnson must now self-isolate for 14 days
If you’re told to self-isolate by NHS Test and Trace or the NHS COVID-19 app the Government guidance states:
- self-isolate for 14 days from the day you were last in contact with the person who tested positive for coronavirus – as it can take up to 14 days for symptoms to appear
- do not leave your home for any reason – if you need food or medicine, order it online or by phone, or ask friends and family to drop it off at your home
- do not have visitors in your home, including friends and family – except for essential care
- try to avoid contact with anyone you live with as much as possible
- people you live with do not need to self-isolate if you do not have symptoms
- people in your support bubble do not need to self-isolate if you do not have symptom
In May Mr Johnson told the Sun On Sunday: “It was a tough old moment, I won’t deny it. They had a strategy to deal with a ‘death of Stalin’-type scenario.
“I was not in particularly brilliant shape and I was aware there were contingency plans in place.
“The doctors had all sorts of arrangements for what to do if things went badly wrong.
“They gave me a face mask so I got litres and litres of oxygen and for a long time I had that and the little nose jobbie.”
Mr Johnson told the paper “the bloody indicators kept going in the wrong direction” and that he kept asking himself: “How am I going to get out of this?”
He said: “It was hard to believe that in just a few days my health had deteriorated to this extent. I remember feeling frustrated. I couldn’t understand why I wasn’t getting better.
“But the bad moment came when it was 50-50 whether they were going to have to put a tube down my windpipe.
“That was when it got a bit . . . they were starting to think about how to handle it presentationally.”
He said he was “in denial” initially about how serious his illness was, and said doctors were right to “force” him to go to St Thomas’s where he spent three nights in intensive care.
After leaving hospital he said “the NHS saved my life no question.”
Labour MP Chris Bryant criticised the Prime Minister for appearing to fail to socially distance in Thursday’s meeting.
He Tweeted: “I don’t understand. I thought England was in lockdown. What was the PM doing not maintaining a social distance with another MP? Have I missed something?”
He added: “I bet Jacob Rees Mogg decides to change the rules in the commons to allow the PM to take part in debates even though he didn’t let Tracey Crouch [An MP diagnosed with breast cancer] take part in a debate on breast cancer.”