Earlier, Chris Whitty said problems with transmitting the virus outside could arise if people gathered in groups, such as huddling around a market stall.
Experts are considering the idea that people should wear masks outside.
Professor Paul Hunter, Professor of Medicine at the University of East Anglia, said: “The risk of transmission outdoors is significantly 18.7 times lower than indoors.
“I would be strongly opposed to wearing masks outside, unless you were to be in a crowd and the examples Chris Whitty gives of snuggling around a market stall and standing in a long line of business. Waiting is probably the only such situation where it can be justified.
Professor Keith Neal, Emeritus of Infectious Disease Epidemiology at the University of Nottingham, said: “The new variant is unlikely to have much effect on outward transmission given the inherently low risk to the exterior with distance. Air movements and the ability to stay away regardless of the infectivity of the virus.