Sir Jeremy Farrar, director of the Wellcome Trust - Britain's biggest charitable funder of scientific research - said the UK was likely to be "one of the worst, if not the worst affected country in Europe".

Sir Jeremy, a member of the government's Scientific Advisory Group for Emergencies (Sage), also told BBC' One's Andrew Marr programme that a second or third wave of the virus "was probably inevitable" and treatment and a vaccine was "our only true exit strategy".

He said a vaccine could be available by autumn but it would take longer to ramp up manufacturing to the scale required to vaccinate many millions of people. "I would hope we would get [that] done in 12 months but that is in itself an unprecedented ambition," he said.