More than 600,000 people using the NHS Covid-19 app in England and Wales were sent self-isolation alerts in the week between 8 and 15 July.
Data shows 618,903 alerts were sent – a 17% rise from the previous week.
It comes as some fully vaccinated key workers will be exempt from self-isolating if they are pinged by the app.
Self-isolation for all fully vaccinated people pinged by the app is due to be scrapped by 16 August, he added.
In England 607,486 alerts were sent to users in the period between 8 and 15 July, with a further 11,417 sent in Wales.
Supermarkets have warned the rising number of retail workers being forced to self-isolate is beginning to affect the availability of some products.
However, Iceland urged shoppers not to panic buy, saying it was not necessary.
“I don’t want people to get the impression that every shelf in every supermarket is bare – that is not the case but we are certainly concerned about instances of shortages, we are looking at the supply chains of critical industries and we are reviewing that situation,” he added.
Supermarkets, and other sectors including hospitality and transport have said growing numbers of staff have been “pinged” by the NHS Covid-19 App which means they have to self-isolate for 10 days. Some companies have reduced opening hours to cope with the staff shortages or shut parts of the business.
Firms want people who have been double vaccinated or have daily tests to be able to return to work.
Downloads of the app continued to rise to 26,826,748 from 26,523,853 the previous week.
It is understood that there is no way to know if the app has been deleted, but #DeleteTheApp has been trending on Twitter today.
A recent poll by YouGov suggested that one in ten users have deleted the app, having previously installed it.
Those aged between 18 and 24 were most likely to have deleted the app, after installing it, according to the data.