Rapid testing for COVID-19 will become the norm in workplaces with more than 50 employees in England, in an effort to control the pandemic.
For employees that cannot work from home, the government has said that lateral flow tests will be made available. They were previously only available for workplaces of more than 250.
These tests produced results in less than 30 minutes.
Health secretary Matt Hancock made pleas on Sunday for businesses and employees to take up the offer in order to stem the spread of the virus.
He said: "When you consider that around one in three people have the virus without symptoms and could potentially infect people without even knowing it, it becomes clear why focusing testing on those without symptoms is so essential."
"We are already working with many employers to scale up workforce testing, spanning the food industry, retail sector, transport network, and across the public sector too.”
Government officials said that the move is an effort to “normalise” testing in workplaces.
A website is now available for businesses to register for rapid testing.
Watch: Mass COVID-19 testing to be expanded to businesses with more than 50 staff
Currently, 112 organisations are part of the mass testing scheme, with employees being tested at 500 sites, according to the government. These include private sector organisations in the food, manufacturing, energy and retail sectors, and public sector employers such as job centres, transport networks, and the military.
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."
Despite the government’s confidence in this approach, union officials warned that testing is not a “magic bullet” and that Public Health England (PHE) found examples of missed asymptomatic positive cases during the mass testing pilot in Liverpool last year.
Dan Shears, GMB union’s health, safety and environment director, said: “It is vital that employers understand the limitations and take steps to address them.
“Everyone wants to ensure that infectious workers keep away from the workplace, but this means getting the introduction of testing right – with confirmatory testing to avoid ‘false negatives’ and crucially ensuring that all protective measures to reduce transmission are implemented to the maximum.”
While testing ramps up, the government has targeted early-May as its deadline for offering the COVID-19 vaccine to all over-50s.
Almost 11 million vaccination doses had been administered as of Friday and coronavirus infections are beginning to decline across the country, according to several published indicators.
The official estimate of the R number — how many people each infected person then reinfects — is between 0.7 and 1.0 for the UK, with new infections falling by 2% to 5% per day.