Johnson's Chief Medical Officer, Chris Whitty, said that England has "probably reached the limits" of how open it can be, given the number of coronavirus cases in the country. On the surface, it might seem a straightforward case of weighing up which is more important: a quick recovery from the economic downturn caused by lockdown, or students avoiding the "generational catastrophe" that the UN Secretary-General predicted if schools are not reopened. However, this is not how the government sees it. According to numerous UK government sources who were not permitted to speak about policy yet to be announced, here's where Downing Street is currently: First, the calculation has changed now that we have seen exactly how damaging the lockdown has been to the UK's economy. On Wednesday, it was revealed that the UK's GDP had fallen a record 20.4% in the second quarter of 2020. One government minister told CNN: "There is huge harm caused by lockdown itself and that needs to be set against the obvious huge harm caused by the virus. When you set one against the other and realize how low transmissions are among schoolchildren -- how do you justifiably come down on the side of economic catastrophe over schools?" Public health experts have urged governments to treat claims that transmission is low in schools with caution, as it varies between age groups. Second, contrary to the idea that there is a straight choice to be made, it's not a "zero-sum game," one government adviser told CNN. "It's not the case of if pubs and bars are open X will happen and if you open schools Y will happen. If everyone is compliant with the rules of social distancing, cleaning their hands, you can basically have both at once." Third, the two things are not unrelated. "Schools are going back regardless, mostly because parents need to get back to work. Everything has a knock-on effect," said a senior civil servant. Fourth, this disease is here and, despite optimistic signs, there is still no clear idea of when a vaccine will arrive. Government sources say that despite the scale of the tragedy, it is still most dangerous for the elderly and vulnerable. So, if most people can go back to some type of normality, the focus can be on local lockdowns and protecting the vulnerable. In short, the government might try to do everything at once. There will likely be a publicity drive placing "more emphasis on public responsibility both in messaging and enforceability," in order to have a "third way" in which "human behavior is the first line of defense," according to the government adviser. Public health experts fear the country is still not in a position to guarantee doing any of this safely and that come the grand reopening, Johnson could still find himself having to make a choice. There is a widespread belief that the UK's test and trace program is still not up to scratch. Christina Pagel, professor of operational research at University College London, says "a strong cont