Prof Karol Sikora, a leading cancer specialist, warned that thousands more people would die of the disease and heart problems if the country was kept locked up.
He is urging ministers to allow small businesses, shops and garden centres to open first, the Telegraph reported.
He said: “As long as we don’t see a second wave of the virus then we should plan for full operation by the end of May, including opening schools and even bars and pubs with social distancing.”
Prof Sikora added: “I would be aggressive about it. If we don’t do that more people will die from cancer and heart disease.”
He had previously said some restrictions may be able to be lifted this week.
He told BBC News this morning: “We’ve got to get going again to avoid a catastrophe in a year or two’s time.”
But his optimism is countered by more cautious Government scientists, who think that the country must be careful about reopening again.
Health Secretary Matt Hancock said yesterday the NHS would start opening up to non-Covid-19 patients again, with routine operations and cancer treatments restarting.
And he urged anyone who needed help to come forwards and stressed: “The NHS is open”.
Gardening shops and recycling centres could be among the first places to re-open, as long as strict social distancing measures stayed in place, it was reported today.
The Telegraph also claimed that the Department for Transport were looking at recommending masks for everyone using public transport to stop the spread of the bug any further.
As HOAR reported last week, SAGE scientists have said there is evidence that wearing masks can stop the spread among people who don’t show symptoms of coronavirus.
Ministers are still mulling over whether to change official guidance to urge Brits to wear them.
This week Boris Johnson is set to explain more detail on how some of the lockdown measures could be changed, after Scotland and Wales started to discuss their plans.
Yesterday he said that civil servants had been planning for the second phase of the lockdown for weeks.
The Cabinet will get a range of options from scientists to explain the impact of how they could be changed, while keeping the rate of transmission low.
Downing Street has warned some could be strengthened and others relaxed in the coming weeks.
The Government legally has to review the lockdown measures by May 7.