Major police federations have slammed the assumption that officers will be on the frontline enforcing mask-wearing inside of shops and supermarkets, calling it “impossible”, “unrealistic”, and “absurd”.

On Monday, Prime Minister Boris Johnson announced that he will make wearing masks compulsory in shops and supermarkets from Friday, July 24th. Police have been given new powers to enforce the anti-coronavirus measure, able to fine those in contravention of the rules by up to £100.

Health Secretary Matt Hancock confirmed that masks will not be mandatory in workplaces or schools, saying that they are ineffective in such circumstances when in long-term proximity to others, stating: “We are not proposing to extend masks to offices.”

Environment Secretary George Eustace has also said the rules will not apply to pubs and restaurants “because obviously, people have got to eat”.

While ministers had implied that police would take on the extra duty of ensuring mask-wearing in shops, senior figures in policing said that it the rule would be “impossible” to enforce and that it would be “absurd” to expect already-stretched forces to patrol the aisles of Asda and Tesco, looking for rogue maskless shoppers.

John Apter, chairman of the Police Federation of England and Wales, said: “To expect my colleagues to be policing the supermarket aisles, looking for those shoppers not wearing a face covering, is unrealistic and unfair.”

Metropolitan Police Federation chief Ken Marsh told BBC Radio 4’s Today programme on Wednesday that “this cannot all be laid on the shoulders of the police yet again”.

“…it will be night-on impossible for enforcement because you won’t have a police officer on every shop door because there isn’t enough of us,” Mr Marsh continued, adding: “If a shopkeeper calls the police because someone hasn’t got a mask on, they haven’t got the power to detain them so that person can just walk away.

“We’ll be driving around and around London looking for people who aren’t wearing masks, it’s absolutely absurd.”

Mr Marsh added that shopkeepers will have to take some responsibility for enforcing rules, while Mr Apter said that police should only be getting involved as a “last resort”.

Officers are likely also concerned at the perception of police enforcing lockdown measures, after widespread criticism for forces’ draconian policing of otherwise law-abiding Britons at the height of the pandemic.

Police sources speaking to The Guardian also said that they had not been consulted before the proposed measures were announced. Martin Hewitt, Chair of the National Police Chiefs’ Council, said on Tuesday that “we were unaware that the announcement was to be made last night”.

Sources speaking to The Mirror have warned that masks in shops could be compulsory until 2021 when it is hoped a coronavirus vaccine will be developed.

One Cabinet source told the newspaper: “We are not doing this with a timeline in mind. This is part of the new normal.

“Until we get a vaccine, we are going to have to be doing a lot of these things.

“We are not going to be doing this for a few weeks and then giving up. It’s part of a wider package of measures, such a social distancing.”

While another government source added: “I don’t think anybody can know how long it will be, but you have to assume we’ll be wearing masks for a while.”