Covering the face can spare you from calamity, says virus expert

‘If the scientists say this is actually what people need to do, then we will absolutely ask people to do that’

goal of mask wearing “is to reduce transmission rates so that less than one new person is infected by every infected person”.

“The use of masks that achieve this would permit social and economic life to resume in every area where masks became universally used,” he said. “This would save us trillions of pounds. Masks will cost a few billion. Masks can literally save us from calamity.”

Prof Yuille added that a mask offered “the possibility of an exit strategy”.

“A lockdown offers no possibility of itself to an end until the vast majority of the population have had the infection,” he said. It comes as Sadiq Khan, the

Mayor of London, called for people to wear non-medical face masks as “additional protection”. “Where this is really helpful is in stopping the virus spreading in a place where you can’t keep your social distance,” he said.

Meanwhile, Grant Shapps, the Transport Secretary, said the Scientific Advisory Group for Emergencies (Sage) were reviewing the evidence on masks.

“If the scientists come out and say, ‘Yep, this is actually what people need to do’, then, fine, we will absolutely ask people to do that,” he said. Sir Patrick Vallance, the Chief Scientific Adviser, confirmed that the Government would look at the evidence again tomorrow “and hope to make some advice around whether changes are needed”.

The UK advice on face masks is currently in line with World Health Organisation guidance, which does not recommend their routine use. However,

many scientists believe that the fact the virus can spread without symptoms showing means that masks may be more useful than would be the case in other illnesses.

Last week, a Cabinet source told this newspaper that although the Government was being “led by the science”, public pressure would also influence a decision.