Only six days earlier, during the daily Downing Street conference on March 24, Dr Harries had responded to a question that went to the heart of the matter – whether couples living apart could socialise.
“If the two halves of a couple are currently in separate households, ideally they should stay in those households,” Dr Harries replied, calling on couples to “test the strength of their relationship” and move in together if they wanted to see each other.
The Government did not want “people switching in and out of households – it defeats the purpose of the reduction in social interaction, and will allow transmission of disease”.
If that was not clear enough, Mr Hancock added: “There you go. Make your choice and stick with it.”
Prof Ferguson’s relationship with Ms Staats is hardly conventional. She is understood to be in an open marriage with her husband, an academic. The couple live in a £1.9 million house in south London with their two children.
Ms Staats has told friends she does not believe their actions to be hypocritical because she considers the households to be one.
According to a friend, Prof Ferguson has met her husband and they share an interest in data science. The 51-year-old epidemiologist is married with a son but it is understood that he and his wife live apart. He is said to have met Ms Staats through the online dating site OkCupid more than a year ago.
Ms Staats, 38, grew up in Isny, south Germany, went to university in Berlin and came to London in 2003 to obtain a masters in Asian Politics from the School of Oriental and African Studies, where her husband works.
She is a senior campaigner at Avaaz, a global online activist network which has been praised by Gordon Brown, Tom Watson, Martin Schulz, the president of the European Parliament, and Al Gore. She delivered a petition to Downing Street that called for an end fossil fuel subsidies to Downing Street during the coalition government and has campaigned against Brexit.
In 2017, Ms Staats was pictured protesting outside Parliament next to puppets of Theresa May and Rupert Murdoch while holding a banner that read: “Stop Murdoch pulling the strings.”
Prof Ferguson is a regular guest on the BBC Today programme. Ms Staats told friends she was at his home on the morning of March 30, when he appeared in the 7.50am slot.
Over the next eight days he continued to appear on the programme, and on April 4 told listeners: “Clearly we want to move to a situation where, at least by the end of May, we can substitute less intensive measures for the current lockdown we have now… I don’t think anyone wants to lift measures at the current time and risk the epidemic getting worse.”
Yet on April 8 Ms Staats was once again at his flat. The contradiction in what he said in public and did in private did not seem to bother the professor, for on April 10, again speaking on the Today programme, he said: “We clearly don’t want these measures to continue any longer than is absolutely necessary.
“I mean, the economic costs, social costs, personal and health costs are huge, but we do want to find a set out policies which maintain the suppression of transmission of this virus.”
On Tuesday night, Prof Ferguson admitted he had made an “error of judgment” and resigned from his Sage role.
He said he “acted in the belief that I was immune, having tested positive for coronavirus and completely isolated myself for almost two weeks after developing symptoms”, adding: “I deeply regret any undermining of the clear messages around the continued need for social distancing to control this devastating epidemic.
“The Government guidance is unequivocal, and is there to protect all of us.”
But with millions of couples spending their seventh week in separation, news of Professor Lockdown’s trysts will be a bitter pill to swallow.