A group of leading scientists has warned that a 1 June reopening of schools would be too early for pupils to return to classrooms safely.
The 'Independent Sage' committee, chaired by former chief scientific adviser Sir David King, has carried out new modelling showing that the risk to children would be halved if ministers delayed their planned school opening date by two weeks.
The committee says the later reopening date would allow for more time for an effective "test, trace and isolate" programme to be established.
"There is no clear evidence that these conditions are met. Until they are, it is not safe to open schools on 1 June," the report says.
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Its modelling found that delaying school opening by two weeks approximately halves the risks to children from Covid-19, and that if the wider opening of schools was delayed until September it would be even less risky, reducing the risk to children to below the possibility of death through a road traffic accident.
The report found that further modelling is needed to identify risks to specific regions. It notes that as many children, teachers and school staff are from black and minority-ethnic communities, which have been shown to be at an increased risk of dying from Covid-19, "it is important to consider the locality-based Covid-19 infection and death rates as the best indicator of the risk from any future school-based outbreaks. We plan to have modelled these effects before we release our full report next week".
The report also highlights the need for a "real-time" response to test, track and isolate data, with plans in place to close schools again if need be.
"This should not be seen as a failure or a cause for blame. It’s inevitable in a pandemic that new outbreaks will occur. Planning for such reclosure is essential and must include measures to maintain educational opportunities for pupils," the report says.
It also highlights the need for more publicly available local data on infection rates, describing this as a "critical gap in the current management of the pandemic".
"The crucial factor allowing school reopening around the world has been the presence of well-functioning local test, trace and isolate protocols – something that is now accepted will not be in place in England by early June," the report says.
It notes that school opening in other countries such as Denmark was introduced after substantial investment in measures such as additional washing facilities.
The government has previously stated that it aims for Reception pupils, as well as pupils in Years 1 and 6, to return to primary schools from as early as 1 June.
It is today due to the publish the scientific evidence underpinning its plan from its own official Sage (Scientific Advisory Group for Emergencies) committee.
The decision by Independent Sage to publish its own modelling on the same day will only add to the pressure on the government to think again.
Last night, Tes revealed how academy trusts that had previously defended the government's plan were breaking ranks because they say they need more time to prepare for opening.
"Scores" of local authorities are reported to be either advising against the 1 June date or leaving the decision up to schools. And the government's own scientific advisers have stressed the need for a full track and trace to be in place before pupils go back.
An Independent Sage committee member told Tes that the committee had reviewed concerns from parents over how social distancing would operate within schools.
"This is integral and essential to the success of opening schools and for keeping them open," they said.
Tes understands that some attending the government's briefing on the scientific basis for reopening schools last Friday were astonished by the lack of up-to-date scientific guidance.
The most recent scientific evidence presented was from 7 April, which would be eight weeks old by the time schools reopened on 1 June, a source said.
The independent committee's report proposes that local innovation is needed to give all children educational opportunities, with suggestions including the requisitioning of school playing fields, sports clubs, community facilities and football stadiums for use by schools.
The committee says public consultation is "essential" when making this decision, and will therefore hold a public forum at midday today, in partnership with the British Medical Journal and Mumsnet, hosted by medical broadcaster Dr Michael Mosley. The committee will take questions from the public which will feed into its final report to the government next week.
Paul Whiteman, general secretary of school leaders' union NAHT, said: “Support for a fixed date for school return is vanishing quickly. What is needed now is local flexibility to determine when it is right for schools to open up to more pupils, informed by evidence of what is happening in their own local area."
Sir David King said: “It is clear from the evidence we have collected that 1 June is simply too early to go back. By going ahead with this dangerous decision, the government is further risking the health of our communities and the likelihood of a second spike.”
“However we also recognise that the decision of when to reopen our schools is a careful balance and that it is vital for our young people to get back into the classroom as soon as it is safe to do so.
"The current climate is likely to disproportionately affect the most disadvantaged in society; therefore it is vital that the government also considers innovative ways to help those who need it most.”