The announcement by the prime minister of the closure of all pubs, clubs and restaurants brought an immediate observable reaction in the supermarkets, the shelves of beer were almost completely cleared.

In the local branch of Sainsbury’s, a woman stood holding her smartphone. Anyone standing within ten metres of her could have heard the annoyance with which she spoke. The beer she sought had sold out and she regarded the emptiness as a personal affront. The woman complained to the friend she had called that a case of one of the few beers still available was going to cost her £40. The desire for two dozen bottles of beer and the three large packs of sausages she held in her left-hand suggested that she did not plan to be socially distanced over the weekend.

People have not coped well with the impact of coronavirus. Panic buying has continued; violence has flared up in supermarkets; key workers have struggled to find food to buy; younger people have flouted guidelines and prohibitions.

Within a few days of the beginning of the measures, there is already a restive mood of which the government is keenly aware. The government response has been to deploy more police on public order duties and to be prepared to use soldiers in some situations. However, the prime minister is an exponent of realpolitik, he knows that the clampdown cannot continue indefinitely.

Conducting the daily press conference on Wednesday, Boris Johnson asserted that the tide would be turned in twelve weeks. Since that statement, scientists have lined up to say that this will not be possible, that a year, or even two years, will be required.

Scientifically, those who disagree with Johnson may be correct. Politically, to continue beyond the twelve weeks will be very difficult. In the warmth of an English June, to try to enforce closures, travel bans and curfews will be to invite major bursts of civil unrest.

The prime minister is utilitarian in his views. The greatest good of the greatest number will mean that people will need to be allowed to return to normality. It will be hoped that some degree of herd immunity will have developed, but if there is the choice to be made between risking a greater number of individual deaths, and the social and economic chaos that will arise if the lockdown continues to be enforced, then the lives of the individuals exposed to the virus will take second place to the interests of the wider society.

If the prime minister does not heed the advice of the scientists, it is not because he does not wish to do as they say, it is because he cannot risk doing so. Twelve weeks of closures will make extraordinary demands upon the political leadership, to continue beyond that period would be impossible.