Britain’s biggest union has called for nurseries to close to most children amid pressure on ministers to produce scientific evidence showing they can stay open safely. Unison said nurseries and pre-schools should close to all but vulnerable children and those of key workers, saying that staff and local communities were at risk and describing social distancing as impossible with small children. On Monday the prime minister described schools as “vectors for transmission” as he announced a third national lockdown for England, including the closure of all primary and secondary schools. Unison said nurseries should be treated the same as schools, as in the first lockdown, and that early-years staff should be prioritised for vaccination and mass testing. Tulip Siddiq, the shadow minister for children and early years, in a letter to her Conservative counterpart, echoed the union’s concerns, urging Vicky Ford to “set out clearly and in detail the scientific basis of the decision”. Many nursery staff, childminders and nannies would fear for their safety as infection rates rose around the country, she said. She also asked the government to commit to regular testing of early-years staff and additional PPE. Demand for nurseries and pre-schools has plummeted during the pandemic, as parents keep their children at home through safety fears or financial strain. While the government had continued to provide funding at the level of the number of children who had attended pre-pandemic, allowing many nurseries to stay afloat, this policy stopped this month. Highlighting the financial difficulties the sector has faced as a result, Siddiq called for increased support, warning that many nurseries ran “at a significant loss” during the previous lockdown, and that the new restrictions could “wipe out much of the demand for childcare”. She urged the government to rethink the “misguided decision to change early years funding” saying that to proceed would be a “death knell for many nurseries and childminding businesses”. Neil Leitch, chief executive of the Early Years Alliance, said many workers were extremely anxious about continuing to work. He said: “It is simply unacceptable that the government has yet to produce any clear scientific evidence about the risk of the new strain of Covid, not only to children but to providers and their families as well.” Unison’s head of education, Jon Richards, said: “Social distancing is impossible with young children and the government has yet to publish the scientific evidence to justify ​nurseries being treated differently to schools. The decision seems ​to have been taken with little regard to the health and safety of ​employees. Ministers must treat ​nurseries the same as schools, as in the first lockdown. Staff must be ​a priority​ for vaccinations and mass testing.” A Department for Education spokesperson said early-years settings remained “low risk environments for children and staff”, adding: “Keeping nurseries and childminders open will support parents and deliver the crucial care and education for our youngest children. We are funding nurseries as usual and all children are able to attend their early years setting in all parts of England. Where nurseries do see a drop in income from either parent-paid fees or income from DfE, they are able to use the furlough scheme.”