By G9ija

Boris Johnson Photographer: Simon Dawson/Bloomberg

The U.K. government will not change the settings on the Covid-19 mobile phone app that’s being blamed for forcing hundreds of thousands of people to isolate at home, undermining efforts to reopen the economy.

In the first week of July, 520,000 people were “pinged” by the NHS Covid-19 bluetooth app after coming into contact with someone who had tested positive for the disease.

Ministers initially said they were reviewing the sensitivity of the settings to avoid people being caught out and told needlessly to stay at home.

But on Monday, Johnson’s officials said the technology is working to prevent the spread of the disease, with about one in three people told to isolate then going on to develop Covid-19.

“The app is doing what it is designed to do,” Johnson’s spokesman, Max Blain, said on a call with reporters. He confirmed the government will not be adjusting the sensitivity of the app’s contact-tracing function.

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Johnson is likely to face demands to explain his government’s approach when he holds a press conference at 5 p.m. on Monday. He is currently isolating at his Chequers country residence, about 40 miles (64 kilometers) outside London, after he held a meeting last week with Health Secretary Sajid Javid, who announced he had coronavirus on Saturday.

Johnson sparked a furious storm on social media by initially attempting to avoid the isolation rules and take part in a trial program that would have enabled him to continue going to work while taking daily tests instead.

But he reversed that decision after the wave of criticism and will isolate until July 26, as will Chancellor of the Exchequer Rishi Sunak.

According to the Adam Smith Institute, 1.73 million people are currently isolating after being contacted by the app, or by other NHS Test and Trace staff, to say they’ve been close to a positive Covid case. That figure could rise to 5.2 million people by mid-August, the research group said.

Business leaders and labor unions have warned transport and other sectors are struggling to cope with worker absences.

Blain told reporters the government needed to “strike the right balance between protecting lives and livelihoods” and will continue to review the way the isolation system is working.

Officials will seek make sure “critical workers” and critical infrastructure can continue to operate, he said.