We should beware. The prime minister has recovered from Covid-19 only to be struck down by a new ailment: morality. Not reopening schools next month, says Boris Johnson, would be “socially intolerable, economically unsustainable and morally indefensible”. The harm done to children’s prospects and mental health would be “far more damaging” than any risk from the virus. “We have a moral duty” to act. When a politician takes refuge in morality we dive for cover. If he now says that a policy he has pursued obsessively for four months harms the prospects and mental health of children, it was bad policy. The largest study so far has shown that only 0.8% of coronavirus patients in hospital have been under 19. If staff or older family members needed protection, that was a different matter from closing schools. Other countries measured the same risk and thought to minimise it by cautiously reopening schools sooner, which also benefitted working parents. Besides, what in Johnson’s other coronavirus policies was “moral”, such as moving thousands of sick elderly people from NHS hospitals to infect others and die in care homes? What was moral about scaring stroke victims away from A&E? Or about deferring treatment for cancer patients, which could lead to up to 35,000 excess deaths? What was moral about denying local authorities the data on which they might run their own test and trace services, which Johnson had boasted was “world-beating” yet has patently failed to deliver? Johnson’s defence of his bad crisis management has always been that “we have been guided by the advice of experts at every stage of our response”, as his government spokesperson put it. Johnson may now accuse his official scientists of timidity and indecision – England’s chief medical officer, Chris Whitty, said 10 days ago that lockdown easing had probably been pushed to its limits. But he took their advice. It was left to Britain’s top paediatrician, Sir Russell Viner, to minimise the risk of school opening. Is Johnson accusing Whitty and co of immorality? This virus is way past its first peak, yet the NHS is still in chaos. Its hospitals are emptying. It is treating just 700 Covid patients a day against 17,000 a day in April, while 10m excluded patients might be on the waiting list by Christmas. Even the wayward infection rate is running at a tiny fraction of the April peak. Talk of a second wave as bad as the first is blatant scaremongering. Johnson is right to assert the primacy of social cohesion and economic sustainability in matters of public policy, except that his job was to think of them from the start. He should keep his morals out of it. • Simon Jenkins is a Guardian columnist