Image copyright Getty Images Image caption Clapham Common in London was among the parks across the UK busy over the weekend Image copyright Wales News Service Image caption Crowds have also been heading for the coast, including to Barry Island
“Don’t think fresh air in itself automatically provides some immunity,” Mr Johnson said, adding that even if people think they are invulnerable, “there are plenty of people you could infect”.
“Take this advice seriously, follow it, because it’s absolutely crucial. ”
“My message is you’ve got to do this in line with the advice, you’ve got to follow the social distancing rule – keep 2m apart.”
Asked whether stricter measures could be introduced, Mr Johnson added: “I don’t think you need to use your imagination very much to see where we might have to go, and we will think about this very, very actively in the next 24 hours.
“It’s so important that that pleasure and that ability is preserved but it can only really be preserved if everybody acts responsibly and conforms with those principles of staying apart from one another and social distancing.
“If we can’t do that then, yup, I’m afraid we’re going to have to bring forward tougher measures . “
Some parks have already announced they will be closing. Essex County Council will close all its country parks from 20: 06 GMT, while earlier Richmond Park in London closed to traffic on Sunday, although those on foot and cyclists were still allowed.
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Media caption Saturday was the “busiest ever visitor day in living memory” in Snowdonia, officials say
Earlier, Scottish First Minister Nicola Sturgeon said the new measures to prevent the spread of coronavirus should not be considered “optional”.
“Life should not feel normal,” she said , and if it did you should ask “if you are doing the right things.”
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