Dominic Cummings today admitted he went back into 10 Downing Street in person hours after visiting his sick wife.
The PM's top advisor revealed he went into the heart of government, in person, despite visiting his wife Mary because she "felt she might pass out".
He said he ran out of 10 Downing Street and drove home on March 27 because "she told me she suddenly felt badly ill, she vomited and felt she might pass out".
He admitted she "might have Covid", though she did not have a cough and a fever, and he believed there was a "distinct probability" he was already infected.
Yet when she felt "a bit" better that afternoon, Mr Cummings returned to work at 10 Downing Street - directly against guidance for those who might have the virus.
Hours later, on the morning of March 28 - and after he and his wife drove 260 miles to Durham - Mr Cummings fell ill with suspected coronavirus himself.
The admission raises fresh questions about the judgement of the Prime Minister's top advisor.
Official advice is for you and your entire household to isolate for 14 days if one person has suspected coronavirus symptoms.
Mr Cummings even admitted there was a "distinct probability that I had already caught the disease", because Boris Johnson had tested positive the night before.
Yet Mr Cummings defended his actions, saying his wife "did not have a cough and a fever" - the two main symptoms of Covid-19.
"We didn’t know whether she had Covid or not," he said.
He said that evening he discussed the situation with his wife - including the fact that many in Number 10 had developed coronavirus symptoms.
He was worried that if both he and his wife fell ill there was "nobody in London we could reasonably ask to look after our child and expose themselves to Covid".
The pair then decided to drive up to stay in a cottage on a family farm.
Boris Johnson's top aide made the comment in a bombshell 14-minute explanation of his actions during a press conference in the No10 rose garden.
Mr Cummings offered no apology for driving 260 miles to his family's farm in Durham when his wife Mary's coronavirus symptoms began on March 27.
Instead he said he believed "I have behaved reasonably" - because he feared his child could not be cared for if they both fell ill.
“No, I have not offered to resign," he declared. “I have not considered it.”
Mr Cummings also admitted he drove from the Durham home to nearby Barnard Castle on Easter Sunday - a half hour drive.
He claimed it was on Day 15 since illness struck, and was to test his eyesight before going back to London down the A1.
He said his vision had been "a bit weird" so his wife suggested to "drive down the road" to check it.
“It was reasonable and sensible to make a short journey before embarking on a five hour drive”, he said.
"We walked about 10-15 metres from the car to the river bank nearby. We sat there for about 15 minutes - we had no interactions with anybody," he said.
But he admitted his wife and child got out of the car midway home so his son could use the toilet.
Mr Cummings said he sought medical advice before the trip back to London - but admitted he didn't before his 260-mile trip up to Durham.
Asked why he didn't just try to drive home, and turn back if he was feeling ill, he said: "We didn't think of doing that, to be honest. We thought 'let's whizz down the road and see how we feel'."
Mr Cummings said a witness who told the Sunday Mirror they saw Mr Cummings on April 19 in County Durham was mistaken, and that he did not return to work after returning to No10 on April 14.
Of the "inaccurate" claims, he claimed the media were “told they were wrong and reported them anyway”, despite No10 not responding before publication.
Mr Cummings admitted: “People like me who helped make the rules should be accountable for their actions”
But he denied breaking the rules, saying: "I did what I thought was the right thing to do."
Speaking at a grilling in the garden at Downing Street, he said: "I don't think there's one rule for other people, as I said I knew what the guidance was, it talks about exceptional circumstances with small children and I believe I behaved reasonably and legally."
Mr Cummings said he, his wife and son stayed for 14 days inside a separate property on his family's farm - leaving for a walk in the woods on private land, and then for the trip to Barnard Castle.
He also left the house to pick up his son from hospital, after he fell ill and Mr Cummings had to call 999. His son stayed one night in hospital.
Mr Cummings said "in a very complicated situation, I behaved reasonably".
He added he was uncomfortable about leaving his wife and child in their London home because he has been subject to "threats of violence".
“I thought the best thing to do in the circumstances was drive to an isolated cottage on my father’s farm," he said.
He said he did not ask the PM about his decision on March 27 - but told him the following week when they were both ill.
"In retrospect it would have been better to set this out earlier on," Mr Cummings admitted. "In retrospect I should have made this statement earlier."
The unprecedented statement in the No10 rose garden came after more than 20 Tory MPs demanded Mr Cummings resign or be sacked over his 260-mile drive to Durham in late March.