Britain will be forced to impose more restrictions on outdoor exercise if people flout lockdown rules designed to curb the spread of the coronavirus, the health minister says.
Daily exercise, such as walking, running or cycling, is allowed as long as people maintain social distancing.
But any other activity such as sunbathing could put others at risk and prolong the lockdown, Health Secretary Matt Hancock said on Sunday.
Most people were complying, he said, but if a minority continued to break the rules "we then might have to take further action".
"What we are doing is being absolutely clear that the current rules must be followed," he told a daily media briefing.
There were fears that warm spring weather on Sunday could encourage Britons to head to parks.
London's Lambeth Council closed Brockwell Park on Sunday after it said many people had sunbathed or gathered in large groups there on Saturday.
Hancock said it was "unbelievable" to see a small minority flouting the government's advice to maintain social-distancing.
Britain's death toll rose to 4934 on Saturday after 621 people died in the previous 24 hours.
A total of 195,524 people had been tested of which 47,806 tested positive, the health ministry said.