Why Britain must unlock on 21 June

The scare over the Indian variant of coronavirus this week is a taste of what to expect over the next few weeks, months or even years. Like all RNA viruses, Covid-19 mutates and has done so thousands of times already. New strains supplant old ones and, for a while, questions will be raised when one mutation comes to dominate. Is it more lethal? Is there a chance it could evade vaccines? Every time so far, there has been no significant reason to doubt the efficacy of the vaccines. So the government’s timetable for lifting Covid restrictions holds firm.

How far should Britain go to try to fend off new variants? Some in government wish to use the country’s vaccination success to follow Australia’s example and allow loose restrictions internally but impose very tight controls on borders. This idea — for Britain to become a hermit kingdom — is gaining some traction inside government. That is why the public has been asked not to go on holiday except to a handful of countries. Other ministers argue that the success of the vaccination programme should allow Britain to live without fear of any known Covid strains.

Matt Hancock, the Health Secretary, is leading the charge for tighter travel restrictions, citing the ‘precautionary principle’. If in doubt, hunker down. But without estimating the costs of border closure, no sensible decision can be made.

Keeping the borders sealed in this way is no small matter. The ability to travel has always been fundamental to Britain’s economy and society. Today a quarter of British children have at least one foreign-born parent, which gives an indication of our social and familial links to the rest of the world. Britain is a global business and travel hub in a way that Australia simply is not.