Downing Street has been warned that the "pingdemic" has led to panic buying and forced one in five workers at some supermarket chains to isolate, as calls mount for self-isolation rules to be relaxed before August 16.
The Telegraph has learnt that, at a crunch meeting with supermarkets last week, ministers were told that the impact was hitting rural, tourist and coastal areas hardest.
During the meeting on Thursday, chief executives in the food industry are understood to have highlighted that the Co-op’s absence rates nationally are now above 20 per cent as a result of staff being sick with Covid or self-isolating.
Waitrose is also said to have warned that it had begun to see panic buying on the back of images of empty shelves caused by problems with deliveries and disruption to supply chains.
Industry bosses said stores were concerned that the recent rollout of lateral flow testing to keep depot staff in work did not go far enough, as workers in stores were not covered.
The warnings were relayed to Nadhim Zahawi, the vaccines minister, and George Eustice, the Environment Secretary, who were joined at the meeting by officials from Number 10 and the Department for Health.
It came as ministers on Monday met to discuss allocating a further 1,200 daily contact testing sites to critical workers in a number of sectors, enabling them to avoid self-isolating if they are identified as a contact of someone with Covid.
Supermarket depot staff were last week given access to 500 sites in response to fears of food shortages, with the critical worker list expanding on Friday night to include train and lorry drivers, police officers and border officials.
The decision was taken after the number of people in self-isolation after being pinged by the NHS app hit a record 619,000 last week, creating chaos for train operators, police forces and other critical sectors.
Despite mounting calls from MPs and business leaders, the Government has refused to bring forward the date for releasing double vaccinated Britons from self-isolation rules from August 16.
Instead, a meeting of the Covid O Cabinet subcommittee on Monday agreed to more than double the number of testing sites to 2,000, meaning more sectors will be covered. They include vets, prisons staff, binmen, energy and chemical workers, telecommunications personnel and well as people working for HM Revenue and Customs.
However, the latest list does not include supermarket on-site staff – risking a fresh confrontation with the industry.
A senior industry source said: "We heard a lot from the Government about opening up and saying the rules won’t last longer than necessary, but so far we’ve seen little action. In reality, the nation’s food supply is under threat and little is being done by the Government to deal with it."
Others singled out Sajid Javid, the Health Secretary, for criticism. A Whitehall source said: "Submarine Sajid seems nowhere to be seen and is leaving it to other departments to mop up his mess.
"This pingdemic issue has impacted a range of sectors and it’s been left to Defra and the Home Office to deal with something that’s led by health. Everyone is asking where Sajid is."