The government is planning to make the NHS Covid app less sensitive to avoid seeing millions of Britons forced to self-isolate over the summer.
The head of the UK Health Security Agency told MPs that work was under way to decide whether smartphone notifications could be “tuned” differently to reduce numbers being “pinged”.
Jenny Harries’ comments came as it was revealed that the weekly figure for people receiving messages via the app telling them to isolate hit a record of more than 360,000 across England and Wales.
The total for 24-30 June was up 62 per cent on the previous week and represented more than one-eighth of all tracing alerts sent out to people who have come in close contact with someone testing positive since data was first published in January.
And figures are expected to rise sharply in response to soaring infections with the Delta variant of Covid-19, which hit 32,551 on Thursday and are predicted by health secretary Sajid Javid to soar to at least 100,000 a day following the lifting of lockdown restrictions in England on 19 July.
Meanwhile, Scottish first minister Nicola Sturgeon said that Boris Johnson’s decision to ditch mandatory face-masks in public transport and confined spaces would not be coming “any time really soon” north of the border.
Ms Sturgeon said the PM’s big-bang removal of all restrictions was “something of an exception” at a time of steeply rising infections.
And she warned that publicity over so-called “freedom day” could cause confusion in Scotland, where some restrictions will remain in place.
In an apparent jibe at Mr Johnson, she said: “My job is not to take the easy decisions in a quest for popularity, it is to do what I think is most likely to keep the country as safe as possible as we get to the end of the vaccination programme.”
The bid to rein in “pings” was launched after warnings that millions of Britons could be ordered to stay home between 19 July and 16 August, when fully-vaccinated people and children will be exempted from self-isolation orders.
Mr Johnson was unable to deny that the total could reach as many as 3.5 million a week when challenged in the House of Commons.
Hospitality and business leaders have reacted with horror to the prospect of huge numbers of staff being unable to work and potential customers being out of circulation just as they try to get back to normal after 16 months of depressed trade due to Covid restrictions.
Chancellor Rishi Sunak said he recognised that “most people’s concerns rest with how the app is working” rather than with separate phone contacts from the test and trace system.
“The health secretary is aware that that accounts for the majority of people who need to isolate, I understand, on the numbers,” Mr Sunak said. “He’s looking at what the most appropriate balanced and proportionate approach to isolation is in these circumstances.”
And Dr Harries told the House of Commons Public Accounts Committee that she was aware of people deleting the Covid app from their phones to avoid being “pinged” as a contact of someone testing positive for the virus.
She said: “We have a piece of work ongoing at the moment, because it is entirely possible to tune the app to ensure that it is appropriate to the risk.
“When the app came into action we know it has been hugely successful but it has been utilised in a world where we did not have vaccinations.
“So working through what a vaccinated population using the app means is something that we are actively doing at the moment.”
Dr Harries said the app was there “for a purpose, not for annoyance”. She said the app had resulted in 500,000 cases of the disease being detected and it was important that people continued to use it.
Mr Johnson said he understood the frustration of people “pinged” and told to isolate, but added that 16 August is “not too far off” for those who are double jabbed.
“I know how difficult it has been for people and I’m sorry for the hassle that people experienced as a result of this – it is coming to an end,” he said.
“What we want to do is just keep going for a little bit longer … As the health secretary has said, we are moving now from self-isolation, from quarantine approach, to test and release approach. The day is not too far off.”
Labour has warned Britain risks a summer of “chaos and confusion” because of the government’s approach, while Tory MPs say the policy on self-isolation will make a mockery of the lifting of restrictions on 19 July.
Responding to suggestions the app could be tweaked, shadow health minister Justin Madders said: “It’s hard to square these comments with a more transmissible Delta variant.
“We need clear messages from ministers about how contact tracing will work this summer - not mixed messages. With predictions of 100,000 cases a day we urgently need an effective contact tracing system.”
And Lib Dem health spokesperson Munira Wilson said: “The success of the vaccination rollout means that the current self-isolation system must be tweaked to recognise that so many have had both jabs.
“Self-isolation has to work for everyone. For those on low incomes that means increasing the amount of financial support available and for those that are double jabbed it means a relaxation of the rules.”
Mr Javid said it was clear the UK was “going through a wave” of coronavirus, but that rising cases had been expected.
“I think [infections] will be a lot higher by 19 July than today, and into August they’re going to be even higher than that,” he told a conference of the Local Government Association.
But he added: “The vaccination is doing its job. It’s a wall of defence… It is severely weaking the link between hospitalisations and case numbers. It means we can start opening up.
“There are people who are anxious, who want us to be more cautious. I absolutely get that. But if you don’t open up now, then when would you do it?
“All the public health officials, all our scientists say it’s much better opening up going into the summer, for lots of reasons, than waiting to do it in the winter.”
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