The health secretary, Matt Hancock, has claimed coronavirus is “in retreat across the country” as the number of recorded deaths among people testing positive for Covid-19 fell to the lowest daily level since before the lockdown was announced. A further 55 people died after contracting the virus in the UK, the lowest daily total reported since 22 March, though there is often a reporting lag over the weekend and government figures do not include all Covid-19 deaths across the country. For the first time since the early days of the outbreak, London hospitals reported no new deaths from the virus, though NHS England said a small number of deaths in the capital over the weekend had yet to be registered. Scotland and Northern Ireland also reported no new deaths in the past 24 hours, while Wales reported three further deaths in the same period. “When you look across the board, it is clear that coronavirus is in retreat across the country,” Hancock told the Downing Street press conference. “But we must be vigilant and we must be cautious, and we are taking a safety-first approach.” He added: “It means that we can proceed with our plan of making some changes, for instance looking towards the proposals that have been made next week on the retail sector, and that people can have confidence to take their children to school in the three years that we’ve opened so far.” Jason Oke, a senior statistician at Oxford University who compiles coronavirus data, welcomed the figures but warned that reporting delays over the weekend often led to lower death numbers on Sundays and Mondays. “The numbers surprised me; I thought we’d see more deaths, and the fact that there are so few outside hospitals, it seems, is particularly positive,” Oke said. But he cautioned that even as deaths trended downwards, they were likely to continue for some time yet. There were more than 500 people on mechanical ventilator beds and more than 7,000 people in hospital in the UK, Oke said, meaning that low numbers of daily deaths were possible for the foreseeable future. “I’d be amazed if we get to no deaths at the end of June,” he said. Rowland Kao, a professor of veterinary epidemiology and data science at Edinburgh University, said the figures were a positive sign but pointed out that they reflected infections caught before the latest easing of restrictions. “It must be remembered that these deaths are a result of infection events that occurred weeks ago, many of them likely when we were still under tighter lockdown restrictions,” he said. Martin Hibberd, a professor of emerging infectious diseases at the London School of Hygiene and Tropical Medicine, echoed the concern and said the UK’s numbers were still high. “While the numbers thankfully seem to be trending down for now, they are still relatively high compared with other countries such as Germany, and unfortunately do not indicate future consequences of today’s actions, as they have the longest lag period of any of the indicators used to track Covid-19,” he said. “As a result of this delay, these numbers should not be used to support current policies, but rather used to reflect on what was in place six weeks ago. I hope the numbers look even better in six weeks’ time, but worry that by then they may be rising again due to increased, perhaps undetected, transmissions that will be occurring this week due to a more relaxed attitude to social distancing.”