Boris Johnson has signalled his support for cutting the Covid self-isolation period to five days.
The Prime Minister said the Government was "looking at" slashing the quarantine period from seven to five days - but would follow the scientific advice.
Education Secretary Nadhim Zahawi became the first top Tory to publicly call for a move to a five-day isolation period on Sunday, following a similar decision in the United States.
It comes as schools and other key sectors have been struggling with staffing shortages as Covid infections soar.
Chancellor Rishi Sunak and several other senior Tories, including Transport Secretary Grant Shapps and Business Secretary Kwasi Kwarteng are reportedly supportive of the move.
Mr Johnson confirmed ministers were considering the plan on a visit to a vaccination centre in his Uxbridge constituency.
Asked if he saw the benefits of reducing quarantine, the PM told reporters: "Yes of course, we are looking at that and we will act accordingly to the science as we always have."
Keir Starmer said he would back a cut in the quarantine period if it was supported by scientists.
The Labour leader, who is self-isolating following a positive Covid test, told reporters: "I'll be guided by the science on this.
"If the scientists and the medical experts say that it is safe to reduce the period of self-isolation then I would be inclined to support it."
Downing Street said it was part of "the ongoing request that we keep all the evidence under review.”
UKHSA and Cabinet Office Covid task force “will continue to look at the evidence for what is the right period of isolation”, the PM's spokesman said.
“If it is possible to go further, then we will do so”, he said.
Cautious optimism has been growing in Government since Boris Johnson held off imposing further restrictions over Christmas.
Attention now appears to be turning towards learning to live with the virus, with reports of a new plan in the works for the Spring.
No10 said it was "too early" to say whether the virus was becoming endemic, where it would continue to circulate but poses less danger.
Meanwhile, Mr Johnson said lateral flow tests would continue to be made available following reports the Government was looking to axe universal free provision.
"We are going to have to make sure we continue to use testing as one of our most important lines of defence for as long as is necessary," Mr Johnson said.
"The other line of defence in addition to testing is of course getting vaccinated. The boosters are going well.
"We have now done 36 million boosters - 90% of people over 50 - but clearly there is an opportunity for people who have not been boosted."
The PM added: "We've got to make sure that we see off Omicron, we are making great progress."
The UK Health and Security Agency (UKHSA) said in a statement earlier this month that it was difficult to compare the US and the UK, as in America the isolation period begins at a positive test, whereas in the UK the clock starts ticking once symptoms start.
It said: "Our modelling suggests that 10-30% of people will still be infectious on day 6, depending on how soon after developing symptoms they received their PCR or LFD test result and the result of their LFD on that day.
"Therefore, our current assessment is that shortening the isolation period further beyond the current 7 days (including end of isolation assurance testing) would be counterproductive. In some settings, such as hospitals, it could actually worsen staff shortages if it led to more people being infected."
