"Morrisons will bar customers from entering its supermarkets without a face covering, unless they have a medical exemption. Sainsbury’s also said it would challenge customers not wearing a mask."

Is this going to be a game-changer ? Can't see that it is from my shopping experience, in the six months or so since masks were introduced I've shopped in supermarkets at least once a week, sometimes twice, I've yet to see a customer NOT wearing a face mask.