The pandemic has saved its cruellest blow yet for the moment when newly-approved vaccines gave hope that the end was finally in sight. Millions of Britons have been phoning friends and family to cancel holiday visits after Prime Minister Boris Johnson imposed new restrictions in England, and other UK nations tightened their own. Faced with a highly infectious new virus strain, in effect “cancelling Christmas” for large parts of the country appears sadly unavoidable. But the U-turn, just days after Mr Johnson assured a planned easing of restrictions would go ahead, will make many feel the government is yet again behind the curve.

The prime minister was late in imposing the first lockdown in March, a delay that a senior epidemiologist has suggested cost tens of thousands of lives. He rebuffed experts’ calls in September for a short, circuit-breaker lockdown that might have arrested Covid-19’s spread. An alternative tiered, regional approach was late and messy in its implementation.

The result was a longer national shutdown in November. But it is now clear that, thanks to the new strain, cases began rising again in south-east England even before that lockdown was lifted. As cases accelerated and scientists raised alarms, Mr Johnson last week said it would be “inhumane” to scrap a five-day Christmas lifting of controls — mocking Labour leader Keir Starmer for proposing otherwise. His last-minute reversal sent thousands to train stations trying to leave the south-east before restrictions kicked in, increasing infection risks. It will also escalate the economic damage.