People will need to wear a face covering in sandwich shops in England under new regulations due to come into force on Friday.
The Department of Health and Social Care confirmed face coverings will be needed in shops such as Pret a Manger if people intend to take their food and coffee away.
If they sit down to eat or drink, they will be able to remove their face covering in that area.
It is likely takeaway outlets will fall under the same criteria.
A Department of Health spokesperson said: “From Friday 24 July, it will be mandatory to wear a face covering in shops and supermarkets, as is currently the case on public transport.
“If a shop or supermarket has a cafe or a seating area to eat and drink, you can remove your face covering in that area.”
The regulations, which are enforceable by the police, are due to be set out on Thursday afternoon.
The same exemptions as for public transport will apply, with children under 11 and people with breathing problems not required to wear a covering.
Anyone who cannot put on, wear or remove a face covering because of a physical or mental illness or impairment or disability is also exempt.
The public are advised to wash their hands before putting a covering or mask on or taking it off, and to avoid touching their eyes, nose, or mouth while wearing one.
Face coverings should be stored in a plastic bag until they can be washed or disposed of, the Department of Health said.
The government has been accused of creating confusion over whether face coverings must be worn in sandwich shops and takeaways.
Health secretary Matt Hancock announced on 14 July that wearing a face covering in shops and supermarkets will be compulsory from Friday, with anyone failing to comply facing a fine of up to £100.
But the prime minister’s official spokesperson later said sandwich shops were exempt.
Hancock said last week: “You do need to wear a face mask in Pret because Pret is a shop. If there’s table service, it is not necessary to have a mask. But in any shop, you do need a mask. So if you’re going up to the counter in Pret to buy takeaway, that is a shop.”
But the prime minister’s official spokesperson later said: “We will be publishing the full guidance shortly but my understanding is that it wouldn’t be mandatory if you went in, for example, to a sandwich shop in order to get a takeaway to wear a face covering.
“It is mandatory… we are talking about supermarkets and other shops rather than food shops.”
In Scotland, face coverings are already mandatory in shops.
Liberal Democrat health spokesperson Munira Wilson said that with just a day to go before the new rules are enforced, the government has created widespread confusion.
She told the PA news agency: “People need a government that can offer genuine reassurances and steer the country to safety.
“After all, clear communication is critical in a public health crisis. Instead, this confusion on guidance shows ministers simply could not organise a bun fight in a bakery.
“All this stinks of ministers making it up as they go along instead of listening to the experts.
“The government must urgently provide the clarity businesses need to operate and people need to feel safe.”
Passengers have been required to wear face coverings on public transport in England since last month.
Former head of the civil service Gus O’Donnell told peers on Wednesday that the government needs to improve its communications.
Giving evidence to the Lords Public Services Committee, he said: “If anyone knows what the clear message on masks is, please tell me.”