Boris Johnson, applauding the NHS on Thursday night, has been urged to consider the cost of the lockdown

Britain has “painted itself into a corner” with no clear exit strategy from the coronavirus epidemic and needs to reconsider herd immunity, according to a senior government adviser.

A prolonged lockdown risks causing more suffering than the virus itself, Graham Medley, the government’s chief pandemic modeller, has warned. He said that the country needed to face the trade-off between harming the young versus the old.

It came as the death toll in the England rose to 3,939 after a further 637 people in England who tested positive died — including the country’s youngest victim – a five-year-old child, NHS England said.

This afternoon Michael Gove announced that University College London and Mercedes Benz will have produced 1,000 new non-invasive ventilators by Monday and will produce