A smartphone app to trace the spread of coronavirus will be trialled on the Isle of Wight this week before being rolled out more widely later this month, the Government has announced.
Transport Secretary Grant Shapps said around 50% to 60% of people will need to use the software for it to be effective as he described it as the "best possible way to help the NHS".
The NHSX app is part of the Government's test, track and trace strategy and will be central to its efforts in slowing the spread of coronavirus.
Contact tracing has been used extensively in South Korea, Hong Kong and Germany, where outbreaks have been contained more quickly.
The Government intends to use the app and a phone team to carry out the tracing.
It will be downloaded on to smartphones and use bluetooth technology to work out when other app users are in close enough proximity to potentially spread the virus.
The data is recorded under an anonymous ID, rather than by the person's name.
If and when someone starts showing symptoms, or tests positive for Covid-19, they are able to share that on the app.
The app then sends a notification warning of possible infection to all those phone users to have come in requisite proximity recently.
Mr Shapps told Sky's Sophy Ridge on Sunday: "The idea is that we will encourage as many people to take this up as possible.
"This is going to be a huge national effort and we need, for this to work, 50% to 60% of people to be using this app.
"Not everybody has a smartphone and I appreciate that for various reasons not everybody will download it but it will be the best possible way to help the NHS."
He stressed the app will be completely confidential.