Sir Patrick Vallance: 'Room for improvement' in test and trace

There is "room for improvement" in the UK test and trace scheme, the government's chief scientific adviser has said.

Speaking at the Downing Street coronavirus briefing, Sir Patrick Vallance said: "Effectiveness of test and trace is less when the case numbers are high".

It comes as figures showed just 15.1% of people who were tested received their result within 24 hours.