NHS figures show 541 people were alerted by the app in the seven days to June 30. For the following seven days, to July 7, the figure was 1,238 – an increase of more than 128 per cent. At Prime Minister’s Questions on July 7, Labour leader Keir Starmer warned that large numbers of people could soon be asked to self-isolate, with major consequences for businesses. He said: “How many people will be asked to self-isolate if there are 100,000 cases a day?” And yesterday, luxury car maker Rolls-Royce said it was ‘extremely concerned’ by the number of employees at its West Sussex site being ‘forced to self-isolate’ by the NHS Covid app. Adur and Arun also saw increases in the number of people receiving alerts from the Covid app. There was a 90.7 per cent increase in Adur, with 845 people ‘pinged’ in the seven days to July 7, compared to 443 the week before. Arun saw a 69.8 per cent jump – 1,443 people were ‘pinged’ in the seven days to July 7. The number was 850 the previous week. Other nearby local-authority areas also saw increases in the number of people alerted. Horsham saw the number of ‘pings’ rise from 737 to 1,385 – an 87.9 per cent increase – while Chichester’s went up by 40 per cent, from 625 to 875.