Shoppers have been told by the government they are expected to wear face coverings from July 19, despite the legal requirement being scrapped in Boris Johnson's so-called "freedom day".
New guidance on workplace safety for when most restrictions in England end says the government "expects and recommends" masks to be worn by workers and customers in crowded, enclosed spaces as the work from home order ends.
The guidance also applies to offices, factories, construction sites and close contact services such as hairdressers.
It comes amid a backlash from regional leaders who have urged ministers to keep masks compulsory on public transport in England.
Both unions and employers criticised the guidance for Step 4 of the Prime Minister’s plan to end the lockdown, with the TUC calling it a "recipe for chaos and rising infections".
Paddy Lillis, the general secretary of the shop union Usdaw, said: "We are very disappointed that the government has not consulted broadly with unions and employers on this guidance.
"So what they have now published, just a few days before it comes into force, provides no assurances for staff or employers. It is a real mess.
"Protection for retail workers through wearing face coverings and maintaining social distancing in busy public areas like shops should be backed up by the law."
"We're respecting the fact that there's a whole variety of different settings across the country"
The government has defended the guidance saying they were "trusting" the public and businesses "to do what's right for them and their staff."
Communities Secretary Robert Jenrick told ITV News: "We're respecting the fact that there's a whole variety of different settings across the country and, if we're going to be living with the virus for a long time, it's right that we have that more varied approach rather than a one-size-fits-all one where the force of the law stands behind it."
To add to the confusion, Number 10 has once again reintroduced the idea of vaccine passports.
In the guidance, table service is recommended to continue in bars, while pubs, restaurants and nightclubs are encouraged to check vaccine and testing status as a condition of entry through the NHS Covid Pass.
Mr Johnson previously suggested such certification would only be recommended in "nightclubs and other venues with large crowds".
Dr Roger Barker, policy director at the Institute of Directors, said bosses are "understandably confused" as he criticised "a series of mixed messages and patchwork requirements".
"Return to work or continue to stay at home. Throw away your masks or continue to wear them.
"Today’s long-awaited guidance from government has done little to dispel that confusion," he said.
Businesses have begun to take things into their own hands, but have few powers to enforce recommendations.
Sainsbury’s said it would encourage customers to continue wearing masks in its supermarkets, with the workplace guidance on masks stating it does not just apply to staff.
Waterstones also said it would encourage customers to wear face masks and observe social distancing when in its book shops.
Airlines Easyjet, Ryanair and British Airways have confirmed they will require customers to wear masks on their planes, while Eurostar will maintain the current policy on coverings.
The confusion comes as the PM is under increasing pressure to reverse his plan to end the legal requirement for masks.
London Mayor Sadiq Khan said their use would be enforced on the capital’s public transport as a "condition of carriage", in a move backed by Transport Secretary Grant Shapps.
Labour metro mayors for West Yorkshire, Greater Manchester, Liverpool City Region, North of Tyne, West of England and South Yorkshire also said they would require or encourage the use of masks on their transport networks where their limited powers allowed it.
But they warned that without a continued national mandate there would be a "ridiculous mismatch" of rules across the country that will be "confusing" for passengers.
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Greater Manchester Mayor Andy Burnham said: "We remain of the view that the best solution is for the government to maintain a requirement of face coverings on all modes of public transport and we call on them, even at this stage, to return to that position."
Masks are to remain mandatory in Scotland and Wales.
The face covering confusion comes as England's travel lists were updated - with disappointment for many after the Spanish islands were moved to the amber list.
On Wednesday, the government also reported the highest daily rise in Covid cases since January 15 when an extra 42,302 lab-confirmed Covid-19 cases in the UK were announced.
A further 49 people had died within 28 days of testing positive for Covid-19 as of Wednesday, bringing the official total to 128,530.
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