The controversial test and trace system is set to be diluted within days over fears the economy will be hammered by too many staff absences.
Ministers are rushing to tweak the app, amid fears that thousands of people will simply delete it to avoid getting the dreaded ping.
Those alerted by the app are told to self-isolate for ten days if they have spent more than 15 minutes within two metres of someone who tests positive for Covid-19.
An algorithm identifies the ‘risk’ to everyone who came into contact with the infected person at any time from two days before they first displayed symptoms.
Figures from yesterday showed a record 50,000 people per day were ordered to isolate by the app last week.
Experts have warned that up to 3.5million people could be asked to stay at home every week if daily cases rise to 100,000 this summer as predicted.
It is understood that Health Secretary Sajid Javid is looking at reducing the app’s sensitivity, sources told the Daily Mail.
One way of doing this is allowing fully vaccinated people to spend longer in close proximity with someone who has coronavirus before they are pinged, due to the extra protection they have.
Jenny Harries, head of the UK Health Security Agency, told a panel of MPs the app was being tuned to reflect the country’s vaccination rate.
She told the Public Accounts Committee she is ‘aware that people are choosing not to use the app’ and urged them not to abandon it.
It comes as business leaders warn the economy could struggle this summer if there are too many staff absences.
NHS leaders have also called for an exemption for doctors and nurses to ensure enough people are on the frontline.
The Health Secretary said on Tuesday that the system would change so that contacts of Covid cases who’ve had both doses won’t have to self-isolate at all.
To the dismay of many businesses and Tory MPs, this will only come into effect from August 16.
But yesterday Chancellor Rishi Sunak hinted that a change could be coming, adding that Javid was ‘aware of the frustration’ people are feeling.
He said: ‘We have two different systems for the Test and Trace. We have obviously the NHS one, and we also have the app.
I know most people’s concerns rest with how the app is working and the Health Secretary is aware of that.
‘The app counts for the majority of the people who need to isolate, I understand, on the numbers and he’s looking at what the most appropriate, balanced and proportionate approach to isolation is in these circumstances.’
Kate Nicholls, of the trade body UK Hospitality, welcomed the app’s review but said people should be able to end their self-isolation if they later test negative.
She said: ‘We need a test-to-release scheme to support advisory pings. This is not just a hospitality issue – it is affecting the whole economy.’
Ms Nicholls added that the high level of self-isolating workers was already causing ‘carnage’ for pubs, restaurants and bars.
Iceland supermarket boss Richard Walker said easing self-isolation rules could help avoid a ‘s**t show for business’.
He added: ‘Our Covid-related absences are growing exponentially. Within a week or two they’ll be the highest ever.’
Absences in hospitals are also said to be ‘rapidly rising’, with NHS Providers chief executive Chris Hopson saying ‘we won’t be able to do everything’ if daily cases were to reach 100,000.
Prime Minister Boris Johnson defended the app yesterday and urged people to continue using it to help keep infections down.
He said: ‘I know how frustrated people are about this and I know people are obviously fed up with Covid restrictions.
‘But we have to be prudent, we have to be cautious, and one of the ways of restricting the spread of the disease, as you know, is to ask contacts to self-isolate, it’s been going on now for a long time.’