British Prime Minister Boris Johnson's plans for mass Covid-19 testing that might re-open large parts of the economy, known as “Operation Moonshot”, are likely to be ineffective and expensive, Reuters reported scientists as saying.

The scientists said that the government's plans signalled a change in strategy from the “test and trace” scheme that has been plagued by difficulties, but that screening the general population regularly would throw up new problems.

“The evidence for screening is not there. The evidence around the tests is poor and weak at the moment, and needs to be improved,” Professor Allyson Pollock, Clinical Professor of Public Health, University of Newcastle, told reporters.

“We're arguing the moonshot programme really should be paused, until the cost-effectiveness and the value for money of any of these programmes is well established.”