UK is facing a 'cascade' of new coronavirus cases and could be heading toward a 2nd 'hard' lockdown, an expert warns

• The UK could be heading for another "hard lockdown" if the new law banning most gatherings of more than six people is not obeyed, an expert who advises the government on COVID-19 has warned.
• "We really need to act very quickly now to prevent this from growing exponentially," the Imperial College London professor Peter Openshaw said.
• He said the "trickle" of coronavirus cases could turn into a "cascade" if the new rules were ignored, adding that the country "must act fast" to stop the virus from spreading rapidly throughout the population.
• The government says a second lockdown is still a "nuclear option."
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The UK faces the prospect of a second "hard lockdown" if new rules banning large social gatherings are not obeyed, an expert has warned, saying the "trickle" of new coronavirus cases threatens to turn into a "cascade" within days.

Peter Openshaw, an Imperial College London professor who is an expert in experimental medicine and has advised the government on COVID-19, told the Sky News host Sophy Ridge on Sunday that the government "must act fast" to stop the coronavirus from spreading rapidly and urged people to obey new rules banning most social gatherings of more than six people.

"We really need to act very quickly now in order to prevent this from growing exponentially," he said. "And that's the main point, is that we must act fast because it is so much harder to get this sort of thing under control if you delay — even a few days is potentially going to be quite dangerous now at this particular moment."

Openshaw said the daily spread of infections, which increased significantly last week, had returned to "exponential growth." He also cited news that the virus had started to spread again in care homes as evidence that more "hospitalizations and deaths" were inevitable.

Ridge then asked him about measures like the UK's new rule barring six or more people from meeting other than in a handful of settings like weddings.

"I'm afraid it is going to cause pain and suffering for us all to go back to some degree of lockdown, but if we don't do this now, we are going to be right back in hard lockdown in short order," he said. 

The coronavirus' spread is accelerating in all parts of England, according to government figures published Friday.

Statistics from Imperial College London indicate that the R rate — which is the average number of people an infected person transmits the virus to — is at 1.7, indicating exponential growth.

Prime Minister Boris Johnson wants to maintain the current system of introducing local lockdowns in areas, such as Birmingham and Bolton, where infection rates are highest.

Robert Buckland, a cabinet minister, insisted on Sunday that a second national lockdown remained a "nuclear option."