Untested, untraced: how three-quarters of Covid contacts slip through cracks

Statistics show how world-beating' tracing scheme fails to follow up on Covid-19 cases at every step

It was in May that Boris Johnson promised the UK would have a world-beating" test-and-trace operation in place within weeks.

Our test-and-trace system is as good as, or better than, any other system anywhere in the world," he doubled down in July.