The warning comes after tough new lockdown measures were announced for parts of the UK on Friday, as cases continued to rise and as the R number climbed above one.
New measures will see the UK ban meetings of groups of more than six people, applying indoors and outdoors from September 14.
Ahead of the “rule of six” coming into play, the chairman of the body representing rank and file police officers raised concerns about behaviour over the weekend.
John Apter, of the Police Federation of England and Wales, said: “There is a real risk some members of the public will take advantage of the current situation and treat this weekend as a party weekend ahead of the tighter restrictions being introduced on Monday.”
Former chief scientific adviser and member of the Scientific Advisory Group for Emergencies (Sage) Sir Mark Walport, says the UK is “on the edge of losing control.”
He told the BBC Radio 4’s Today programme: “I think one would have to say that we’re on the edge of losing control.
“You’ve only got to look across the Channel to see what’s happening in France, what’s happening in Spain.
“The French on Thursday had 9,800 new infections and one can see their hospital admissions and indeed their intensive care admissions are going up.
He added: “The short answer is the only way to stop the spread of this infection is to reduce the number of people we all come into contact with, that lowers the risk.
“It’s a very very fine balancing act, it’s very important to get youngsters back to school, people to university, but it means we’re going to have to hold back our contacts in other areas.
“Where people can work from home there’s an extremely strong argument that they should do so.”
Cabinet Office Minister Michael Gove told BBC Breakfast: “If people do behave in a way that is not really in line or in tune with the guidelines that have been put out, then they are putting other people at risk.
“The reason why the country’s police chiefs have said that they hope people behave with appropriate restraint this weekend is we do not want to see a further acceleration of the spread of the virus.
“There’s a range of scientific opinion but one thing on which practically every scientist is agreed is that we have seen an uptick in infection and therefore it is appropriate we take public health measures.”