No wonder supermarkets don’t all agree on how to approach face mask enforcement. They’re being told to go left, go right and stay where they are, all at the same time.

In banning non-mask wearers, several supermarkets last week bowed to government pressure over unfounded concerns their stores are a vector for transmission. This week they’ve been told by the Equality and Human Rights Commission they’re at risk of discriminating against disabled people by doing so. Not only that, but there is no legal obligation for disabled customers to show evidence of medical exemption and supermarkets shouldn’t routinely ask them to, the Commission’s executive director Alastair Pringle said in his letter to supermarket CEOs.

Of course, some disabled people cannot wear masks, such as those with autism or respiratory conditions, as Pringle’s letter points out. Unfortunately, with no one required to show evidence, refuseniks simply unwilling to comply can also claim exemption without proof, rendering the whole exercise in banning non-mask wearers pointless.

It’s a point Iceland MD Richard Walker highlighted when he tweeted: “Despite statements made by some supermarkets, banning non-mask wearers isn’t realistic while there are medical exemptions: no one is demanding proof of these. We ask all customers to wear masks but I WILL NOT put our staff at risk trying to refuse entry to aggressive refuseniks.”

Guidance from the same government that wanted the bans also says providing evidence “is a personal choice and is not necessary in law”. But just in case someone should choose to, the government also provides exemption cards and badges for anyone to download and print, no questions asked.

Maybe the government should make up its mind what it wants before it blames supermarkets for not delivering it. It’s not ministers who will end up being sued for discrimination.

Equally, perhaps Pringle should have addressed his letter to ministers, rather than supermarket bosses.