Some scientists advising the British government are warning that a planned move to ease COVID-19 lockdown measures in England risks being implemented too soon.
Several members of the UK government's scientific advisory group have voiced concerns after an expert in infectious diseases spoke out to say the move was "dangerous". Two more have warned respectively that the lid on a "boiling pan" is being lifted, with the risk that the country may "lose control again".
The UK has the highest number of confirmed deaths and infections from coronavirus in Europe.
The government has responded by defending the easing of restrictions. From Monday in England, groups of up to six people from different households will be allowed to meet outside, in parks or private gardens, as long as two-metre distances are kept.
Some primary school children will be able to return to school, while the government launched its contact tracing system earlier this week.
Professor John Edmunds, a member of the UK's SAGE (Scientific Advisory Group for Emergencies) committee, expressed concern over the country's ability to contain the spread of the coronavirus under these new measures.
He said the most important issue was the high number of cases still being reported, citing an estimate from the Office for National Statistics (ONS), which said that there may have been on average 8,000 new infections per day in England alone between 11-24 May.
This is several times higher than the official government figures, and takes into account undetected cases where symptoms are mild or absent.
"Even if we don't get a second peak and we just keep the incidence at this level that will still result in large numbers of infections over time," Edmunds said, adding, "and people will die."
Sir Jeremy Farrar, another SAGE member, added his support on Twitter for the comments, saying "COVID-19 is spreading too fast to lift lockdown in England". He said infection rates would have to come down, and testing and tracing operations fully working, before such a move could be made safely.
On Saturday two more SAGE members told BBC Radio that they agreed. Professor Peter Hornby warned it was vital "we don't lose control again". Calum Semple of the University of Liverpool said "essentially we're lifting the lid on a boiling pan and it's just going to bubble over".
But at the daily COVID-19 briefing, Culture minister Oliver Dowden defended the planning easing of restrictions, saying government policy continued to be led by science.
It was "absolutely right to urge caution", he said, adding that the government would not implement such a move unless it was confident of doing so in a safe way.
Boris Johnson announced the move to ease lockdown rules in England on Thursday, after several days dominated by the controversy surrounding the alleged breach of regulations by his top adviser Dominic Cummings.
London Mayor Sadiq Khan tweeted his support for Jeremy Farrar's warning, saying he was "deeply concerned we are now rushing too fast to lift lockdown measures". He disagreed with the UK prime minister's assessment that the five tests for easing the country's COVID-19 lockdown had now been met.
The five tests include providing sufficient critical care to patients, seeing a sustained fall in daily death rates, having proof that the rate of infection is going down, being confident in testing capacity and PPE supply, and being confident that an adjustment to measures will not risk a second wave of the epidemic.