More than half a million people were pinged by the NHS Test and Trace app in a week, the highest figures ever.
A total of 520,194 notifications were sent to users of the app in the week to 7 July, informing them that they had been in close contact with someone who had tested positive for coronavirus.
The figures reflect a 46 per cent rise on the previous week, up from 356,677, and is the highest weekly figure since data began being recorded.
Unite has warned that some factories are at risk of having to shutdown after employees are being “pinged” by the NHS app.
People must isolate for 10 days if they are deemed to have been in close contact with someone with the virus by the app.
Some companies are rumoured to be missing 20 per cent of their workforce.
The government is said to be exploring plans to lessen the sensitivity at which the app is currently alerting people.
Communities secretary Robert Jenrick said the government is “concerned” by the numbers being pinged.
Jenrick told LBC radio today: “It is important that we have the app, that we take it seriously, that when we do get those messages we act accordingly.”
A poll conducted by Savanta ComRes suggested that a third of people aged 18 to 34 have deleted the app.