Discontent with the Government’s self-isolation policy is growing as food industry bosses condemned changes to ease the “pingdemic” as “worse than useless”, hospitality leaders warned of a summer of closures and train operators were forced to cut services.

There were increasing calls for Boris Johnson to bring forward his wider relaxation of quarantine rules for the fully vaccinated from August 16 as businesses were hampered by staff being told to isolate as coronavirus cases soar.

In a bid to calm the concerns of industry, ministers published a limited list of sectors whose double-jabbed workers are eligible to avoid isolation if they undergo daily testing before the wider easing of rules for England.

Industry leaders said the move did not include sufficient workers, but doctors warned the problem is that the Prime Minister has let the virus “rip” and not the “pings” being issued by the NHS Covid-19 app to tell coronavirus contacts to isolate.

The mounting criticism came as data from the Office for National Statistics (ONS) showed Covid-19 cases continued to rise, with around one in 75 people in England infected.

The estimate of the number testing positive – 741,700 – in the week to July 17 is the highest since the week to January 30.

In the emergency measures to protect supplies, around 10,000 workers in the food sector were expected to be included in the scheme for fully vaccinated workers to be exempt from isolation if they test negative. Others in key sectors of the economy and vital public services were also included.

But British Frozen Food Federation chief executive Richard Harrow raised concerns that more workers may be freed up in some areas of the supply chain but not others such as in supermarkets.

“It shows that yet again Government does not understand how connected the food supply chain is. Only opening part is unlikely to solve the overall issue. Plus, who is in and who is out, who decides and how do they decide?” he told the PA news agency.

“Confusion continues to pervade and I have been advised no list until Monday. This is worse than useless.”

Iceland managing director Richard Walker said he was “deeply disappointed to see supermarket store workers omitted from the list”.

To facilitate the new isolation rules for critical workers, the Government said daily testing for workplaces in the food supply chain was being extended to frontline emergency services and some transport workers, with an extra 200 testing sites expected.

But reduced timetables were being introduced on railways across England to improve reliability after a spate of last-minute cancellations due to staff self-isolating, with more than 600,000 people in England and Wales told to quarantine by the app in the week to July 14.

Transport for London warned of line closures and cancellations this weekend, with more than 300 members of staff isolating, while Thameslink, Southern and Avanti West Coast will have slimmed down services from Monday.

Cornwall Airport Newquay was being “very much affected” by staff shortages due to isolation orders and its boss was not optimistic over discussions over exemptions with the Department for Transport.

Managing director Peter Downes told BBC Radio 4’s Today programme: “We’ve been told to expect exemptions in very small numbers of people, in ones and twos, rather than large numbers of staff.

“When we have between a quarter and a third in some cases of individual teams being pinged by the system in one go, and as soon as you get people back you’re often losing others to fresh notifications, we don’t believe that the scheme is going to cater for that.”

One industry not to feature in the exemptions list was hospitality, with its trade association warning the sector will have “one hand tied behind our back” as staff are forced into isolation over Covid-19 contacts during what should be the peak season.

Calling for a “more pragmatic solution”, UKHospitality chief executive Kate Nicholls said: “We now face a summer of venue closures and reduced service, when we should be at a seasonal peak. The sector will do all it can to provide great service, but it will be with one hand tied behind our back.

“Those who are fully vaccinated should be able to test after a ping and, subject to a negative result, carry on with their lives. For those not fully vaccinated two negative tests should be sufficient to return to work.”

London mayor Sadiq Khan joined business leaders to add to demands to “immediately” loosen the rules for fully vaccinated people alerted by the NHS Covid-19 app.

Conservative former health secretary Jeremy Hunt said the Government risks “losing social consent” for isolation if it does not immediately bring forward the wider relaxation of quarantine rules.

His call was echoed by fellow Conservative Greg Clark, a former business secretary who now chairs the Commons Science and Technology Committee.

“We know that on August 16 a new system will come in, in which you can take a test if you’re named as a contact and only isolate if you’re positive – I don’t see why we can’t begin that now on July 23 rather than wait,” he told the BBC Radio 4’s World At One programme.

But the British Medical Association said the problem was not the “excessive pinging” of the NHS Covid-19 app but that the Government’s coronavirus strategy has caused “rocketing case numbers”.

Its council chairman, Dr Chaand Nagpaul, said isolation numbers are the “direct result of lack of effective measures by Government that is allowing the virus to let rip throughout the nation”.

The Local Government Association said directors of public health were already being overwhelmed with queries from employers who believe their staff should be exempt.

Services provided by local authorities such as bin collections, road repairs and park maintenance could be hit, the council representatives warned.