June 26, 2021 - 8:55am

Matt Hancock said last week that the reason why the government was maintaining the quarantine requirement on those arriving from amber or red countries who are fully vaccinated was that “when only half the population has been offered the jab then it is not fair in many ways to offer extra freedoms for some”. Grant Shapps repeated that line on the Today programme yesterday, pointing out that some people can’t be vaccinated or can’t prove that they have been (for example, if they have been vaccinated abroad).

However, the government’s powers to impose isolation or quarantine depend, like almost all government powers, on the statute that confers them. The statute here is the Public Health (Control of Disease) Act 1984. Section 45B of that Act — the power that the government relies on — gives Ministers the power to make regulations that provide for the “isolation or quarantine of persons”. But, for present purposes, that power can be used only for the purpose of “preventing danger to public health”.

So, when working out whether the government is acting lawfully by maintaining the current quarantine requirements on the double vaccinated, the only relevant question is whether they are maintained in order to prevent danger to public health. If the scientific evidence is that people who have been double-vaccinated for at least two weeks cannot catch or transmit Covid, and if people can prove that status in a reliable way (as everyone who can download the NHS app can), then it is impossible to see how it “prevents danger to public health” to make those people isolate or quarantine for up to 10 days after arriving from abroad.

The scientific evidence may not, of course be as clear as that. There may be some risk — though, since the requirement seriously interferes with a number of rights protected by the Human Rights Act, the risk would have to be a real one in order to justify that interference.

But the government’s central problem is that it isn’t relying on any such risk: rather, it’s relying on the claim that it isn’t fair to allow some people but not others the freedom to travel abroad and to return home without quarantine. That, though, misses the legal point. It isn’t fair that some people pose much less of a Covid risk than others. But, when using these public health powers, risk is the only thing that matters.

The government has, so far, managed to defend its Covid restrictions in the courts (though the Scottish government lost a case about closure of places of worship). Its powers are very wide. But they still have to be used for a purpose fitting within the terms of the statute. So if Ministers trying to justify not relaxing these restrictions on the double-vaccinated can’t do better than “it wouldn’t be fair”, they may well find themselves at the wrong end of a judicial review.

George Peretz is a QC. His practice covers a wide range of public law.