British Prime Minister Boris Johnson dismissed criticism on Wednesday of his government's plans to implement local lockdowns if there are flare-ups of the novel coronavirus and of an app to trace the spread of the virus.

At prime minister's questions in parliament, the opposition Labour leader Keir Starmer suggested both systems were not for when England is prepared to ease its coronavirus lockdown from July 4.

A spokesman for Starmer pointed to Germany, which has had a large number of people downloading its app, and a number of countries "which are far ahead" in terms of developing their apps, such as Singapore and South Korea.