Health Secretary Matt Hancock said: "With roughly a third of people who have coronavirus not showing symptoms, targeted asymptomatic testing and subsequent isolation is highly effective in breaking chains of transmission.
"Rapid, regular testing is led by local authorities who design programmes based on their in-depth knowledge of the local populations, so testing can have the greatest impact.
Matt Hancock. Picture: PA
"We are now expanding this offer to every local authority across the country, and asking testing to be targeted on workers who cannot work from home during this national lockdown, while asking employers to work with us to scale up workforce testing.