U.K. government's impatience with lockdown risks a second wave of the coronavirus, scientist warns

The U.K. is still at coronavirus alert level 4, meaning transmission is high or rising exponentially. Government policy states that social distancing must remain in place at this level, with "gradual relaxing of restrictions and social distancing measures" not supposed to happen until the country moves down into alert level 3.

However, the country — which has been in lockdown since late March — eased some of its lockdown restrictions on Monday, with people in England allowed to meet outside in socially-distanced groups of up to six and primary schools able to resume classes. Non-essential shops in England are being allowed to reopen from June 15.

On Sunday, 1,936 new cases of the coronavirus were recorded by the British government, taking the total number of lab-confirmed infections in the U.K. up to 274,762 to date. According to government data, 38,489 people who tested positive for the virus had died as of May 31, with 113 new deaths recorded for the day.

Scientists on the government's Scientific Advisory Group for Emergencies (Sage), however, have estimated that there are still around 8,000 new infections happening every day in England alone.

"If we continue with 8,000 infections a day and continue to lift the lockdown, then I fear the risk of a second wave becomes very real," King said. "If we show impatience just as we're getting it under control — and I think the government is showing impatience — the risk of a second wave becomes greater."

While he noted that daily deaths from Covid-19 had fallen from almost 1,200 at the peak of the country's epidemic to around 200, he warned that the government's premature scaling back of its mitigation measures could lead to a resurgence of the virus.

"I fear we can anticipate with the uplifting of the lockdown that this could get worse," he told CNBC, predicting that the "flocks of people" congregating would be problematic in the effort to keep the virus under control.

"Outdoors, two meters apart, that's not a problem, but how do they get to the beach? In coaches, in trains and buses. One person with the virus puts the whole coach full of people at risk," he said.

"We have to be extremely careful — I wouldn't lift the lockdown. We've had nine weeks of good behavior from the public, by lifting the lockdown in any way people are taking their eyes off the importance in carrying on just a few more weeks so that we can get this thing under control."

A spokesman for Prime Minister Boris Johnson said on Monday that the U.K. was unlikely to experience a rise in Covid-19 transmission if the public adhered to the government's social-distancing guidelines, according to Reuters.

Sage advisors warned last week that Johnson's government was being too hasty in lifting lockdown measures. On Friday, health authorities estimated that the R number, or reproduction rate, of Covid-19 in the U.K. was between 0.7 and 0.9.

Any number above one means the virus is spreading exponentially and an outbreak is expected to continue.

King told CNBC that lockdown measures should not be eased until the government's test, trace and isolate capacity had been "brought up to scratch" and tested for at least a week.

On Sunday, the government confirmed it had met its target of carrying out at least 200,000 Covid-19 tests per day.

But while the government's track and trace initiative — which aims to inform people when they have been in close contact with someone who has tested positive for the coronavirus — was rolled out last week, the accompanying app is yet to launch and has already been marred by hiring confusion and privacy concerns. 

Peter Drobac, director of the Skoll Centre for Social Entrepreneurship at Oxford University, also told CNBC in May that governments need to have a strong test, trace and isolate framework in place before lifting lockdown measures.

King added that local communities must be fully engaged in the whole process of the lockdown being eased, but claimed local authorities had "been left out of the considerations of the government until very recently."