From supermarkets to train lines, many have reported staff shortages due to being “pinged” by the app and needing to self-isolate at home, triggering calls for the app’s sensitivity to be dialled down.
However, the vaccines minister has indicated that there would be no changes to the app’s sensitivity, saying on Monday it was right to "clinically advise people, with that sensitivity that they have come into contact with people who have tested positive."
He added: "The difference now that we’ve got almost 88 per cent of people with one dose and 68 per cent of people with two doses, we can make decisions that on August 16 anyone who is double vaccinated doesn’t need to then isolate if they are pinged and don’t test positive for Covid.”
Amid estimates that 1.73 million were isolating on Sunday - including Boris Johnson and Rishi Sunak - Mr Zahawi said those in other professions would have to wait until next month for a reprieve.
"We want to try to get to August 16, where if you’re double vaccinated you don’t need to isolate," he said.
"The August 16 date is for the rest of the economy to allow more people to be protected by two doses."
It comes as Iceland and Greene King said they have had to close some shops and pubs due to staff needing to self-isolate after being “pinged” by the app.
Iceland said that it has now shut some shops because 1,000 staff have been alerted by the app.
Greene King has closed 33 pubs in the past week due to staff self-isolating.
A Greene King spokesperson said: “In the last week alone, we had to temporarily close 33 pubs, which is making it even more challenging to rebuild trade as we reopen and is very disruptive for our team members.”
Over the weekend, it was reported that supermarket shelves could be left empty and Marks and Spencer may reduce opening hours due to the “pingdemic”.
Retailers warned of a "massive disruption" to food supplies and a senior M&S executive told the Sunday Times that there may not be enough staff to open stores because of increasing infections and the number of people self-isolating.
"Our Covid cases are roughly doubling every week and the pinging level is about three to one of Covid cases, so we’re seeing that growing exponentially," he said.
Steve Rowe, chief executive of M&S, added: “If there’s shortages we’ll have to manage it by changing hours of stores, reducing hours.
"Where the industry will see the pain is in the supply chain because logistics runs tight anyway to be efficient.”
Asked about the prospect of supermarket shelves being left empty, Mr Zahawi told Sky News: "I don’t disagree with you, but businesses are rising to the challenge... Key workers and businesses, small, medium and large - it is difficult, this is not a normal year, but the NHS app has proven its worth, and it is saving lives."
Iceland and Greene King have been approached for comment.