Workplace Covid testing is being offered to more companies in England, for staff who cannot work from home during lockdown, the government says.
Businesses with more than 50 employees are now able to access lateral flow tests, which can produce results in less than 30 minutes.
Previously only firms with more than 250 staff qualified for testing.
Health Secretary Matt Hancock urged businesses and employees to take up the offer to “stop this virus spreading”.
A website has been launched for more businesses to register for the rapid testing programme.
It comes as England’s national lockdown continues, and the UK’s daily reported coronavirus deaths and cases remain high.
Business Secretary Kwasi Kwarteng said the expanded workplace testing regime would complement the rollout of Covid vaccines in the drive to “reopen the economy and recover our way of life as soon as it is safe to do so”.
And the British Chambers of Commerce said it would be “working hard to ensure that eligible businesses take up this opportunity”.
Some 112 UK organisations have so far signed up to take part in workplace testing, with employees being tested across 500 sites, according to government figures.
This includes private sector organisations in the food, manufacturing, energy and retail sectors, and public sector employers such as job centres, transport networks, and the military.
NHS Test and Trace will support organisations to deliver the asymptomatic testing by supplying the kits and offering guidance and training for delivery.