Britain is at a tipping point on COVID-19, health minister Matt Hancock said on Sunday, warning that a second national lockdown could be imposed if people don't follow government rules designed to stop the spread of the virus.

COVID-19 cases have risen sharply in recent weeks to more than 4,000 per day. Prime Minister Boris Johnson has called it a second wave and stricter lockdown measures have been introduced in areas across the country — with London possibly next in line.

"The nation faces a tipping point and we have a choice," Hancock told Sky News. "The choice is either that everybody follows the rules ... or we will have to take more measures."