The controversial self- isolation system will be watered down within days, amid fears it will cripple the economy and public services this summer.
Ministers have ordered an urgent review of the NHS app following concerns it is bringing the system into disrepute by ordering too many people to self-isolate.
Sources told the Mail the app's 'sensitivity' will be reduced to cut the numbers being asked to isolate unnecessarily.
Figures yesterday revealed a record 50,000 a day were ordered to isolate by the app last week – more than half of the 85,000 told by the NHS to stay away from others.
At present, those using the NHS app are 'pinged' to self-isolate for ten days if they are found to have spent more than 15 minutes within two metres of someone who tests positive for the virus.
A computer algorithm identifies the 'risk' posed to everyone who came into contact with the infected person at any time from two days before they first displayed symptoms.
It is understood Health Secretary Sajid Javid is looking at reducing the sensitivity of the system. One option is that fully vaccinated people could be allowed to spend longer in close proximity with an infected person before being 'pinged', to reflect the extra protection vaccines provide.
In other developments:
Britain reported 32,551 new Covid-19 cases, up only three on the day before – one of the smallest rises in weeks – and 35 deaths, up two on Wednesday's figure; Double-jabbed Britons were told they can visit amber list countries without having to quarantine on their return; But they were warned of possible six-hour queues to re-enter the UK; Dido Harding tried to defend the disastrous £37 billion Test and Trace system as a 'success'.
A customer uses their phone to scan a QR code for the NHS Test and Trace in the Soho area of London
Experts have warned that up to 3.5 million a week could be asked to self-isolate if case numbers rise to the estimated 100,000-a-day level
A total of 356,036 alerts were sent to users of the NHS Covid-19 app in the week to June 30
The NHS Covid-19 app has now been downloaded more than 25million times but there are fears many people are now deleting it
Department of Health bosses posted 32,551 infections, up 16.3 per cent on last Thursday. Data highlighting the 'vaccine effect' on transmission shows infections across England are still 13 times higher in young people compared to the over-60s
Boris Johnson said the 'day is not too far off' when contacts of positive cases will no longer have to self-isolate, with the current approach to quarantine coming to an end from the middle of next month
Ministers are concerned that failing to reform the system could result in thousands deleting the app.
Business leaders have warned that staff absences through self-isolation could cripple the economy this summer. NHS leaders said health services could also be disrupted and called for doctors and nurses to be given an exemption because 'something has to give'.
Mr Javid announced plans this week to move to a new system that will allow fully vaccinated people to avoid self-isolation. But to the fury of businesses and many Tory MPs, he said the change would not be introduced until August 16.
Experts have warned that up to 3.5 million a week could be asked to self-isolate if case numbers rise to the estimated 100,000-a-day level.
Chancellor Rishi Sunak hinted at the change yesterday, saying Mr Javid was 'aware of the frustration' caused by the self-isolation system.
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.'
The NHS Covid app has been downloaded by more than 26 million people. But anecdotal evidence suggests significant numbers are deleting it or disabling the Bluetooth function, to avoid being 'pinged' unnecessarily.
Boris Johnson yesterday appealed to people to continue using the app, which he said was helping to prevent cases spiralling even higher.
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.'
Kate Nicholls, of the trade body UK Hospitality, welcomed the review of the app, but urged ministers to go further by allowing people to be released from self-isolation if they test negative for the virus.
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.'
Iceland supermarket boss Richard Walker said the difference between lockdown being lifted and self-isolation rules being eased would result in a 's*** show for business'.
He said: 'Our Covid-related absences are growing exponentially. Within a week or two they'll be the highest ever.'
NHS Providers chief executive Chris Hopson called for NHS staff to be exempt from self-isolation unless they test positive. He said if cases rose to 100,000 a day, self-isolation would place 'significant pressure on the NHS', adding: 'We won't be able to do everything.'
Danny Mortimer, deputy chief executive of the NHS Confederation, said there are 'rapidly rising
