Police urge people not to walk in the road and say crossing paths with others will not transmit coronavirus

Police chiefs said on Wednesday that they did not have powers to enforce the two-metre social distancing rules. However, that has not stopped them from being forced to intervene in cases including one in which a couple in Nottinghamshire knocked a six-year-old girl off her bike when they refused to make way on a path.

Councils from Richmond and Lambeth, in London, to Bristol and Manchester have started work to widen pavements, accelerate pedestrianisation schemes and introduce one-way systems for walkers following the Government’s appeal for people to avoid using public transport.

Cyclists are being advised to keep as much as 22 yards apart when behind another cyclist because of research suggesting that droplets from coughs and sneezes can remain in the air.

National charity Cycling UK acknowledged that the research – by scientists from Eindhoven University of Technology, in the Netherlands, and KU Leuven, in Belgium – had not been peer-reviewed or verified by other academics, but said greater distance “may be needed when you are behind someone else”.

The findings, based on analysis of exhaled droplets in wind tunnels, suggested walkers should keep at least four metres clear when following others, runners should stay 10 metres from one another and fast cyclists should ride up to 20 metres apart.

Roger Geffen, the Cycling UK director of policy, said: “Personally I am thinking in terms of at least the length of a cricket wicket [22 yards] when I am behind someone, but I am very reluctant to say there is any science behind that.  “That’s what I am personally doing. I have no idea if it is right.”

Mr Geffen said the charity’s view was that people should be considerate and, when overtaking, allow a “good distance” rather than cutting in rapidly. “You have to leave it to a certain amount of common sense about what a reasonable distance is,” he added.