Coronavirus has changed everything. Make sense of it all with the Waugh Zone, our evening politics briefing. Sign up now.
Speaking on a visit to the London Ambulance HQ on Monday, the prime minister said coverings have “have real value in confined spaces” and that people “should” wear them in shops.
He told reporters there was “growing” evidence face coverings could limit the spread of Covid-19.
But he went on to say his government had yet to make a ruling on whether they should be made compulsory.
His official spokesperson, meanwhile, has said a formal review is under way into whether masks should be made mandatory in public places in England.
At a briefing with reporters on Monday, he said there is further evidence about the “benefits of face coverings in some environments indoors”.
It comes after Cabinet Office minister Michael Gove added to the mixed messaging by saying on BBC One’s Andrew Marr Show that coverings would not be enforced in shops but that wearing them was “basic good manners”.
Johnson said: “They have a great deal of value in confined spaces where you’re coming into contact with people you don’t normally meet.
“The scientific evaluation of face coverings and their importance on stopping aerosol droplets, that’s been growing, so I do think that in shops it is very important to wear a face covering if you’re going to be in a confined space and you want to protect other people and receive protection in turn.”
Asked if it was his personal view that coverings should be worn, he said: “Yes. Face coverings, I think, people should be wearing in shops, and in terms of how we do that – whether we will be making that mandatory or not – we will be looking at the guidance. We will be saying a little bit more in the next few days.”
The PM said coverings had...