BORIS JOHNSON is expected to announce today that the two-metre coronavirus social distancing rule will be relaxed in a decision that would go against the advice of his scientific advisers.

Scientists and Labour have warned of the perils associated with halving the distance, without having health and safety measures – such as a functional coronavirus test and trace system – in place.

Pubs, restaurants, hotels and hairdressers have called on the government to reduce social distancing to one metre to boost revenues when they start to reopen from July 4.

But Dr Susan Michie, Professor of health psychology at UCL, pointed out that the government’s own Sage committee of scientists are against the change.

She said countries that have reduced it to one metre have fully functional testing and tracing systems.

In slamming the government’s failure to roll out a test and trace app after repeated trials on the Isle of Wight, she said that other nations have not “delayed it for months in hope that an untested, de novo centralised private-sector app could do the job.”

Former chief scientific adviser Sir David King, of the Independent Sage group, said that the “risk of transmission is still too high” to reduce distancing indoors.

Campaign group Keep Our NHS Public also criticised the government’s test and trace system, saying that recent data shows that only 25 per cent of contacts of new cases are being reached.

Sage says that 80 per cent of contacts of all symptomatic cases must be found and isolated to stop the virus spreading further.

Shadow health secretary Jonathan Ashworth said Labour is prepared to back reducing the two-metre rule if there was greater use of face masks, face shields for workers and a fully functioning testing and tracing system.