The health secretary, Sajid Javid, has confirmed that the minimum time people with Covid in England have to spend in self-isolation is to be cut to five full days.
From Monday, people would be able to leave isolation on day six if they tested negative on days five and six, Javid told the Commons.
Javid was updating MPs on Thursday, a day after Boris Johnson said a decision would be made on the issue “as fast as possible”.
The government has been under pressure to bring the situation in England into line with the US, where the isolation period has been cut to five days.
The current UK Health Security Agency (UKHSA) guidance is for people with Covid to isolate for at least six full days from the point at which they have symptoms or get a positive test, whichever is first, with release from self-isolation after two negative lateral flow test results on days six and seven. People can leave self-isolation on day seven.
At prime minister’s questions on Wednesday, Johnson said: “We are certainly looking at reducing the isolation period, and we hope to bring you more about that … as fast as possible.”
Javid told MPs that UKHSA data showed about two-thirds of Covid cases were no longer infectious by the end of their fifth day in isolation. “We want to use the testing capacity that we’ve built up to help these people leave isolation safely,” he said.
“After reviewing all of the evidence, we’ve made the decision to reduce the minimum self-isolation period to five full days in England. From Monday, people can test twice before they go – leaving isolation at the start of day six.
“These two tests are critical to these balanced and proportional plans and I’d like everyone to take advantage of the capacity we have built up in tests, so that we can restore the freedoms to this country while we are keeping everyone safe.”
The decision is likely to be welcomed by Tories who have called for the change, and could help ease pressure on the embattled prime minister. It will also help address staff shortages by allowing people to return to work earlier.
UKHSA modelling based on data before the rise of Omicron suggests that 31% of people remain infectious five days after the onset of Covid symptoms or a positive Covid test. Further work by the London School of Hygiene and Tropical Medicine found the risk of being infectious after two negative tests was very low.
“We estimate that the chance you are still infectious after two negative tests is small,” said Billy Quilty, a research fellow in infectious disease epidemiology at LSHTM.
“However, a reduction to the time waited until resuming testing – as has effectively occurred – will likely result in more tests used, as many individuals are still likely to have high viral loads at this point in their infection.
“Based on what we know pre-Omicron, it will take a few more days for many individuals to produce their string of negatives. It remains to be seen how long people will be infectious for and test positive for Omicron.”
Matthew Taylor, the chief executive of the NHS Confederation, said: “This is a pragmatic move which leaders will welcome if it can mean more health and care workers who are well enough can return to the frontline, providing it does not significantly add to the risk of the virus spreading.
“The number of people in hospital is still high, with admissions still rising in the north of England and, alongside that, the NHS faces a huge care backlog and significant vacancies.”
The health service has come under strain in the Omicron wave, with hospital admissions rising at the same time as more staff have been off work with the virus. More than 40,000 NHS staff at hospital trusts in England were absent for Covid-19 reasons on 9 January, more than three times the number at the start of December.