“Around a million people” are currently isolating as a result of coronavirus, a minister has said, as Sky News understands an announcement on the relaxation of testing rules will be announced today.

“We don’t actually collect that data on a daily basis, but it’s obvious if you look at how many people tested positive yesterday, about 215,000, that they’ll all be self-isolating and obviously from the previous days,” health minister Gillian Keegan said.

“So it’s about a million people probably are self-isolating right now.”

It comes as Sky News understands that millions of people who test positive on lateral flow devices will be told they do not need to take follow-up PCR tests, which delay the official start of isolation for hundreds of thousands of people.

Health officials have drawn up plans to limit PCR tests to those with symptoms, allowing those who are asymptomatic – about 40% of cases – to return to work more quickly.

It is understood the move will be announced on Wednesday.

People who test positive on lateral flows will still need to isolate for at least seven days, and Ms Keegan told Sky News people will need to register their positive lateral flow results.

Government sources said lateral flow tests are “highly effective” and testing capacity needs to be prioritised.

Key workers across several industries that keep the country running will be required to take COVID tests daily, Boris Johnson announced on Tuesday.

The prime minister said 100,000 workers in England, “from food processing to transport to Border Force”, will have to test every day they are working from 10 January.