UK Health Secretary Matt Hancock has given details of the performance of England's new test and trace system for coronavirus, saying he's confident it will become "world class".
Data had already been published in advance showing that more than 31,000 people were identified during the first week of the system, with nearly 27,000 contacted within 24 hours and asked to self-isolate.
The contacts were traced from 8,000 people who tested positive, two-thirds of whom gave contact details. Some 25,000 people were recruited to act as tracers and began work at the end of May.
The success of the programme is critical to the country's ability to combat the spread of COVID-19 and prevent a second spike as the nation moves gradually out of lockdown.
Hancock told the daily government briefing that the system acted like "radar" in locating the virus, and its performance so far painted a "positive picture". The minister said people had a "civic duty" to comply with the scheme -- which he has not ruled out making compulsory, in response to concerns over the number of people not passing on details of contacts. He was confident the operation would be "world class", he added.
Critics have highlighted the importance of detecting a high proportion of infections, and of test results being delivered within 24 hours, in order to be able to act quickly to stop the virus from spreading.
The UK has Europe's highest number of deaths from the virus and the slow rate of decline in the infection rate has led the government to ease only partially the lockdown in England.
The UK's devolved nations of Scotland, Wales and Northern Ireland have their own policies.
Watch the briefing from UK Health Secretary Matt Hancock and Dido Harding, head of the test and trace system, in the video player above.