There is evidence face coverings have a “weak but positive effect” in reducing transmission of the coronavirus, Downing Street has said.
Experts have argued coverings are unlikely to prevent someone contracting the coronavirus, but say it may reduce the number of infected people who are not showing symptoms from spreading the virus.
NHS England has announced 352 new deaths of people who tested positive for COVID-19, bringing the total number of confirmed reported deaths in hospitals in England to 20,483.
In Scotland there have been a further 40 deaths (taking the total to 1,515), while there have been 17 more deaths in Wales (925) and 18 more in Northern Ireland (365 total).
Asked about face coverings at the daily Westminster briefing for journalists, the PM’s spokesman said: “Ministers are still considering how we move forward with face coverings in terms of the precise advice which we give to the public and once that’s ready we will announce it.
“The advice we have received based on the science shows a weak but positive effect in reducing transmission of coronavirus from asymptomatic members of the public where social distancing isn’t possible.
“What ministers need to consider is how best to produce advice for the public on the next steps and that work is still ongoing.”
It comes after the PM said face coverings will be “useful” when lockdown restrictions are eased to “give people confidence they can go back to work”.
On Thursday, Mr Johnson said: “What I think SAGE [the government’s scientific advisory group] is saying, what I certainly agree with, is that as part of coming out of the lockdown, I do think face coverings will be useful.
“Both for epidemiological reasons but, also, for giving people confidence that they can go back to work.
“You’re going to be hearing more about that and that kind of thing next week.”
It is understood that ministers are not considering recommending people use medical-quality masks, which could divert supplies away from the NHS.
What kind of materials are advisable to use for such coverings is one of the issues the government is considering.
On Tuesday, the Scottish government issued new advice saying that people should wear face coverings in shops and on public transport.
First Minister Nicola Sturgeon did not make their use mandatory, conceding the evidence over their use is “still limited”.
But she said there were benefits in wearing coverings to reduce transmission from individuals who are not yet displaying symptoms.
Asked that same day whether the recommendation was likely to be adopted across the UK, Health Secretary Matt Hancock said the government’s position had not changed and that there was “weak science” supporting the advice.
Professor Angela McLean, the deputy chief scientific adviser, said SAGE had recommended that there is “weak evidence of a small effect” that wearing a mask can stop an infected person spreading the disease.
She told Tuesday’s COVID-19 news conference: “The answer is clear that the evidence is weak and the effect is small, and we have passed that on to our colleagues in government with which to make a decision.”
Cabinet Office minister Michael Gove has also suggested there may be a danger that people would act in a “cavalier” way if told to wear masks.
“The scientific evidence so far says face coverings can have an effect in preventing an individual from spreading the disease to others if they have it and are asymptomatic,” he told MPs on Wednesday.
“But there is also a worry that some people may think that wearing a mask protects themselves, as distinct to protecting others, and therefore they may behave in a manner that is slightly more cavalier.”