When Boris Johnson appeared before the House of Commons Liaison Committee at 3.30pm on Wednesday (UK time), he made his distaste for a second national lockdown abundantly clear.
Such a measure would be economically "disastrous" and "completely wrong for this country", the Prime Minister told the senior MPs.
Yet despite his rhetoric, Johnson was by no means in denial about the likely consequences of the resurgent outbreak.
In a sit-down interview with the Sun that afternoon, he referred to line graphs appearing to show a second wave as "a double hump" camel, saying the trend would inevitably "feed through to mortality".
How, then, to square the circle?
A few hours later, the chief scientific adviser, Sir Patrick Vallance, and the chief medical officer, Professor Chris Whitty, came to Johnson with what appeared to be a solution.
Warning that the number of deaths would rise significantly by the end of October without further interventions, they proposed a time-limited "circuit break" – essentially curfews and targeted restrictions on activities.
The measures could include asking pubs and restaurants to close for a two-week period or to observe limited opening hours. Crucially, it is understood the plan would keep schools and workplaces open.
Modellers on the Scientific Advisory Group for Emergencies (Sage) believed the package could prevent a return of exponential growth of Covid-19 without kicking the knees out from the economy.
The experts proposed implementing the partial lockdown during the October school half-term, at the end of the month, in order to minimise the indirect impact on education.
Already that day, ministers had signed off new localised restrictions across much of the North East. Newcastle, Gateshead, Sunderland, Northumberland, South Tyneside, North Tyneside and County Durham are among those to be hit by a ban on household mixing and 10pm curfews for restaurants and pubs.
However, on the question of nationwide measures, no final decision was taken. Instead, it is understood aides pencilled in next Friday, September 25, for the Prime Minister to announce future measures to combat the virus, most likely the circuit break to coincide with half-term.
Johnson's instinct to do as little damage to the economy as possible would have been bolstered by his Thursday morning meeting with Rishi Sunak, the Chancellor, and Alok Sharma, the Business Secretary, at which Sunak is understood to have stressed just how disastrous for the public finances a full-scale second lockdown would be.
By Friday morning, however, the view of the situation in Whitehall was changing fast.
Matt Hancock, the Health Secretary, conducted a round of broadcast interview which left no doubt about how rattled some in the Government were by the latest data.
"This is a big moment for the country," Hancock said. "We are seeing an acceleration in the number of cases. And we are also seeing that the number of people hospitalised with coronavirus is doubling every eight days. We are now starting to see the effects in hospital. I fear more people will die."
Over the next few hours, there followed an avalanche of fresh data that appeared to justify the Health Secretary's gloom.
The weekly Office for National Statistics (ONS) infection survey (a relatively small but nationally representative rolling community study) indicated that there were 6000 new cases a day in England between September 4 and 7, compared with 3200 the previous week. It means at least one in 900 people are now believed to have coronavirus.
Meanwhile, Public Health England (PHE) figures going up to September 13 show that the rate of hospital admission per 100,000 in the population has risen among those 85 and above from to 10.2 compared with 5.2 the week before.
Comparable leaps are evident in younger pensioners: 1.5 to 2.2 among 65 to 74s, and 3.3 to 4.6 in the 75 to 84 age group (the graphic below shows infections by age in England).
Perhaps most worrying was the increase in intensive care admissions, which have about doubled.
And, as of Friday, 115 Covid-19 patients were on mechanical ventilators in England – compared with 63 the week before – out of roughly 1000 in hospital with the virus.
Yvonne Doyle, medical director at PHE, expressed the fears of health officials. "We're seeing clear signs this virus is now spreading widely across all age groups and I am particularly worried by the increase in rates of admission to hospital and intensive care among older people," she said.
"This could be a warning of far worse things to come."
Downing Street will also have been aware of the deteriorating situation on the continent, amid fears the UK is following the same path as France and Spain. The infection rate in Spain has hit 292.2 per 100,000 people, and stands at 172.1 in France.
The French government's weekly coronavirus report revealed the country is seeing an increase in Covid-19 deaths "for the first time since the lifting of the lockdown" in May, with 265 people having died from the virus this week compared with 129 the week before.
To what extent which particular piece of data changed the thinking in Downing Street is not known.
However, it is known that, at some point on Friday, Johnson's announcement, planned for next Friday, was brought forward to Tuesday.
It came as Nicola Sturgeon used her Friday briefing to echo Hancock, warning to people to prepare for a swathe of new nationwide lockdown restrictions next week as a "circuit break" to stop the resurgence of coronavirus.
A source said: "We were looking at the figures saying October is too late. There are hawks and doves. The hawks were saying we need to do something in the next few days.
"It's a circuit break, not another national lockdown – unless things turn very bleak. The question is what can we do that is not a lockdown but still puts the skids on Covid? Over the weekend, there will be a lot of work to draw up measures, get the science and all the options out. What can we do that doesn't tank the economy?"
The measures could see a temporary ban on friends and separate households socialising. Pubs and restaurants could be either closed or open for shorter hours.
The prospect of a return to encouraging people to work at home if possible has not been ruled out, but there will be no school closures.
A Government source said closing schools was still viewed as a "last resort" and would only be considered "if the circuit break doesn't work", adding: "The overriding desire is to keep schools open."
Susan Michie, professor of health psychology at UCL and a member of the Government's Scientific Advisory Group for Emergencies (Sage), warned ministers not to repeat the mistake of the March lockdown in implementing measures too slowly.
"We need a stitch in time," she said. "We need to learn the lessons of the spring. Every day's delay to a step change in measures to restrict transmission when it is increasing exponentially will be expensive in terms of health and lives in the short term, and the economy in the long term."