Making the wearing of face masks in shops in England compulsory would be a «reasonable measure», the boss of the Waterstones book chain has said.
However, James Daunt told the BBC it should not be the job of shop workers to «police» the policy.
In Scotland it has been compulsory to wear a covering while inside a shop since last Friday.
On Monday, Boris Johnson said people in England «should be wearing» face masks or other coverings inside shops.
The prime minister said the government would decide in the next few days if «tools of enforcement» were needed.
‘Block the source’
Mr Daunt told the BBC’s Today Programme: «On public transport wearing a mask seems sensible. If the science backs it, then it is a perfectly reasonable thing, and I think people will become more familiar with shopping.»
But he said it «would not be right» to ask staff to enforce the rule.
«There are a tiny, tiny minority of people who will be confrontational over it and it is not the position of shop workers to enter into that situation,» he said.
«And indeed, we would ask our shop workers not to confront someone who is stealing from us, for example. We would call the police.
«We shouldn’t put ourselves in confrontational positions, but I think we can, as retailers, if we are requested to do so, clearly tell everybody it is a sensible thing to do.»
Shop workers union Usdaw has urged the government to clarify its policy on face coverings in shops.
«It should never fall on shop workers to enforce the wearing of face coverings, they are already dealing with more abuse than normal and this could be another flashpoint,» warned Paddy Lillis, Usdaw general secretary.
«We need clarity from the government, the mixed messaging and indecision is not helpful for shop workers.»
Linda Bauld, professor of public health at the University of Edinburgh, told the Today programme that evidence now suggests that wearing masks in confined spaces makes a difference.
«Essentially infections are spread by droplets and they’re relatively large when they come out in a cough or a sneeze but they become much smaller as they travel through the air.
«So the job of a cloth covering isn’t so much to protect the wearer but to block the source of infection,» she said.
She said leaders should lead by example by being seen wearing face coverings and should explain clearly why it is needed or required.
«Enforcement needn’t be heavy-handed. Requiring people to wear masks in shops will give that little extra nudge and make it much clearer for the general public,» she said.
‘Basic good manners’
Last week, Prime Minister Boris Johnson appeared for the first time in public in a mask and hinted that stricter rules were coming in England.
But on Sunday, Cabinet Office Minister Michael Gove said there were no immediate plans to make masks in shops compulsory.
However, on Monday Mr Johnson said: «I think people should be wearing [face masks] in shops.
«And, in terms of how we do that whether we make it mandatory or not, we’ll be looking at the guidance – we’ll be seeing a little bit more in the next few days.»