Chancellor Rishi Sunak has been criticised for wearing a type of face mask described as "worse than not wearing one".
He was pictured wearing the mask in question for a second day despite doctors and professors warning that valved masks "act like jets" that can "create a plume of infection", reports the Manchester Evening News.
The Chancellor was first cautioned about the effectiveness of the face covering after posting a picture of himself leaving a Pret A Manger store on Twitter on Wednesday.
Responses called for him to not wear it, including one from Oxford University Professor Trisha Greenhalgh, who shared: “Not that one Rishi. One without a valve. Way to go.”
When someone else commented the mask was better than none at all, Prof Greenhalgh replied: “No, worse. It makes the exhalation into a jet.”
Former Conservative leader candidate Rory Stewart added: "A little guidance maybe needed on mask types - the key point of masks is to protect OTHERS from your own breathing - many masks of this type have exhalation valves."
Mr Sunak was pictured wearing the mask again during a visit to Jobcentre Plus to see the new support in job centres on Thursday.
Dr Bharat Pankhania, who has more than 20 years experience in infectious disease management, urged people to not wear masks with valves in them as they force a "high velocity flow of air from the mouth out through the valve which could create a plume of infection".
Speaking to LBC earlier this month, he stressed: “We must not wear those masks out in the public, we must not... please stop using them."
A new study has discovered that even homemade masks made with high-quality materials are effective in reducing the spread of the virus for both the wearer and those around them.
Professor Melinda Mills, director of the Leverhulme Centre and author of the study, said: “The general public does not need to wear surgical masks or respirators. We find that masks made from high quality material such as high-grade cotton, multiple layers and particularly hybrid constructions are effective.
“For instance, combining cotton and silk or flannel provide over 95 per cent filtration, so wearing a mask can protect others.”
The Chancellor's photograph of himself at Pret follows images of Michael Gove in a branch of the eaterie bare-faced, which led to confusion about whether masks should be worn in sandwich shops.
While Health Secretary Matt Hancock said coverings would need to be worn in shops in England from July 24, No 10 later said there would be an exemption for takeaway purchases.
Mr Hancock told Sky News: “You do need to wear a face mask in Pret because Pret is a shop. If there’s table service, it is not necessary to have a mask. But in any shop, you do need a mask. So, if you’re going up to the counter in Pret to buy takeaway that is a shop … but if you go to your local pub you can’t go to the bar.”
Prime Minister Boris Johnson’s official spokesman later gave an alternative explanation.
“We will be publishing the full guidance shortly but my understanding is that it wouldn’t be mandatory if you went in, for example, to a sandwich shop in order to get a takeaway to wear a face covering,” he said. “It is mandatory … we are talking about supermarkets and other shops rather than food shops.”
