People have been urged not to have a “party weekend” before the government’s “rule of six” restrictions come into force on Monday. The call from the Police Federation came as a former chief scientific adviser urged the public to act in tune with guidelines as the UK is “on the edge of losing control” of coronavirus, he said. Mark Walport, a member of the Scientific Advisory Group for Emergencies (Sage), said the only way to stop the virus spreading was to reduce the number of people we all come into contact with. He said there was an “extremely strong argument” that home working should continue. Tough new Covid-19 lockdown measures were announced for parts of the UK on Friday as cases continued to rise. They came as the R number, the reproduction number of coronavirus transmission, climbed above one for the first time since spring. Birmingham became the biggest local authority to announce a tightening of lockdown measures and health officials flagged “worrying signs” of infections in elderly people. The latest UK figures showed another significant surge in positive cases on Friday – up to 3,539, compared with 1,940 a week ago. While the number of people dying from Covid-19 remains low, there has been a steady increase in the numbers of patients in hospital in recent weeks. On Friday, it stood at 863, a rise of 120 from the week before. In advance of the “rule of six” coming into play, the chairman of the body representing rank-and-file police officers raised concerns about people’s 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.” Police in Manchester, where a local lockdown has been in force since 30 July, said they broke up a house party of 30 people in the early hours of Saturday. When asked whether the UK was still in control of the spread of the virus, Walport said: “I think one would have to say that we’re on the edge of losing control.” He told the BBC Radio 4’s Today programme: “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. “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.” The professor said he was “definitely” still working from home and told the programme: “Where people can work from home there’s an extremely strong argument that they should do so.”