LONDON (Reuters) – Britain on Thursday said it would switch to Apple and Google technology for its test-and-trace app, ditching its current system in a U-turn for the troubled programme.

The test-and-trace programme is seen as a key measure to reopen the country, but has also been dogged by criticism after the nationwide roll-out of a National Health Service (NHS)-developed smartphone app slipped from the last month towards the end of the year.

Apple and Google have been in talks with Britain about the technology, which uses a decentralised model. The firms have barred authorities using their technology from collecting GPS location data or requiring users to enter personal data.

Those running the programme admitted that the change of tack was unplanned but denied that it was a setback, emphasising that they did not want to rush out an app which fell short of standards.

Apple and Google’s model has attracted the interest of over 20 countries, though some of the restrictions they have imposed have frustrated governments as the world’s top two smartphone makers undercut the technology’s usefulness by prioritising user privacy.

The current UK app is being tested on the Isle of Wight, off the southern coast of England, where it had proved to work well on Google’s Android operating systems but not on Apple iPhones.

Ministers have admitted to technical issues with the app, which meant that it was not ready for use in time for the launch of England’s test and trace system on May 28.

James Bethell, a junior health minister, on Wednesday said, with regards to the app, that the government wished to “get something going for the winter”, but that it was not a priority.

Britain’s adoption of this ‘decentralised’ approach would be in line with a growing number of European countries, including Italy, Switzerland, Germany and Austria.