The vaccines minister has rejected calls to slash the self-isolation period for people who have tested positive for coronavirus from seven days to five.
Business leaders are pressuring the government to reduce the isolation period to help ease mass staff absences caused by the rapid spread of Omicron.
More than a million people are currently in isolation in the UK after testing positive for COVID in the last seven days.
"We always look at the clinical evidence, as you can imagine, and we've recently reduced it from ten days to seven," Maggie Throup told LBC on Tuesday.
Watch: Sajid Javid announces new self-isolation rules for England
"At the moment, we don't feel actually that it's appropriate to reduce it any further because we'd be very concerned people would still be infectious and be able to pass on the disease.
"So I think we've got a measured approach at the moment, where people need a negative test on day six and a negative test on day seven so people are able to go back to work."
The UK Health and Security Agency (UKHSA) reduced the isolation period from ten days to seven days in the run-up to Christmas for fully vaccinated people who have tested negative twice.
Calls to slash the period further came after the Centre for Disease Control (CDC) in the United States made the controversial decision to cut the isolation period in half from ten days to five.
The CDC also say Americans testing positive do not need to test to release, but must wear a mask for a further five days if they have not been boosted.
On the issue of the number of people isolating in the UK, Throup told Sky News on Tuesday that she did not know the exact figure.
“I’m not sure of that (actual) figure, but I think what’s shown over Christmas is that a lot of people have caught the disease, the Omicron variant is very transmissible," she said.
"But what is good news, it doesn’t seem to be resulting in severe diseases as some of the other variants did."
Advocates for the UK taking the CDC's approach say it will reduce the level of disruption and staff absences not just in the NHS, but across all sectors.
Matthew Taylor, chief executive of the NHS Confederation, said the NHS did not want staff going back into hospitals with COVID and risk passing it on.
He told Times Radio that reducing the self-isolation period to five days should only be done if the science “said it was absolutely safe”.
The UK reported 157,758 new COVID-19 cases in a 24 hour period, with cases overall up 50% compared to the previous week. 42 deaths were also reported in the same 24 hour period.
Watch: Vaccines minister: Measures in place to keep schools safe