The government has not provided any specific guidance to older children and teachers, with just days to go before a return to schools, despite evidence showing coronavirus poses a much higher risk to them.
The prime minister has been seeking to reassure parents that "schools are safe" and everything has been done to ensure risk is minimised, but Labour has attacked the government for not providing tailored guidance.
Boris Johnson, in a video released on Twitter, told parents the risk to their children in sending them back to school is “very, very, very small”.
The education secretary said a “very clear system of controls” has been set out so that schools are able to return safely.
With just one week before the PM's planned reopening of schools in England, questions have been raised about why the government has taken a "one-size-fits-all" approach to guidance.
Evidence shows that coronavirus is a mild disease for most children, however there is a much higher chance of negative outcomes in older students and teachers.
When asked why there had been no specific guidance, Education Secretary Gavin Williamson did not provide an explanation.
He claimed the government had been "incredibly clear" with its guidance, which he said had been provided following advice from the UK's chief medical officers.
Asked about comments by Scottish First Minister Nicola Sturgeon that some secondary school teachers and pupils may wear masks in some settings, the Education Secretary said: “We are not in a position where we are suggesting that.
“We believe there is a system of controls there in place in all schools for children to be able to return safely and for staff to be able to operate safely within those schools.”
Labour's Shadow education secretary Kate Green accused the Government of being “missing in action” over schools policy during the pandemic.
“The guidance that’s been given to schools is one-size-fits-all, it doesn’t take account of the fact that a small school, perhaps in very constrained premises will have to make different arrangements from a large inner city school," she said.
“There hasn’t been information for school leaders, so that they can’t plan what they might have to do if there was a sudden spike in the local infection rate and the guidance that has come out I think has been – it’s been contradictory, it’s been confusing, it came very late, shortly before the summer holidays."
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Mr Williamson said closing schools again in areas of any imposed local lockdowns would be “the absolute last resort”, adding how there is more harm done to them by not being there.
Many parents are concerned about the risk to their children and household if they go back to school, where social distancing may be more difficult, but experts have been warning that any more time away from education could have a long term impact on the development of more disadvantaged pupils.
Prime Minister Johnson earlier told parents it is "absolutely vital" that they send their children back to school in September.
Mr Johnson, whose fiancee gave birth to his son Wilfred earlier this year, conceded that "parents are genuinely still a bit worried about their children contracting coronavirus" at school but suggested the risk to youngsters would be worse if they didn't return.
“It’s vital for their education, it’s vital for their welfare, it’s vital for their physical, and indeed, their mental wellbeing," he said, "so let’s make sure that all kids, all pupils, get back to school at the beginning of September.”
He insisted the "risks are very, very, very small that they’ll even get it, but then the risk that they’ll suffer from it badly are very, very, very, very small indeed".
Most children have spent five months or more away from school however disadvantaged children without access to learning materials will suffer more from time off than their peers who have access to laptops and tutoring.
Experts have been warning the education attainment gap between children of different backgrounds will widen, the longer children are kept out of schools.
In a tweet following the video, Mr Johnson said: "Nothing will have a greater effect on the life chances of our children than returning to school."
"It’s vital that parents understand that schools are safe," the PM said in his video, adding that "teachers have gone to great lengths to get schools ready".
He reminded parents that many teachers have had children in their classrooms "throughout the pandemic".“Lots of schools have been open and looking after kids very, very successfully," he said, adding how they "will take steps to ensure that groups aren’t mixed up, that we have washing of hands and all the other disciplines you need to prevent spread of the virus".Many pupils in England have not been to class since March when schools were closed except to look after vulnerable children and those of keyworkers.
Schools in Scotland reopened earlier this month, while those in England, Wales and Northern Ireland are expected to welcome all pupils from the beginning of September.
Earlier, Mr Johnson thanked school staff who "have spent the summer months making classrooms Covid-secure in preparation for a full return in September."
“We have always been guided by our scientific and medical experts, and we now know far more about coronavirus than we did earlier this year."
Deputy Chief Medical Officer for England Jenny Harries reiterated the prime minister's message that the risks of not going to school were far greater than the virus to children.
She told ITV News: "We can't ever say that an environment is 100% safe, but we recognise that concern from parents.
"The UK chief medical officers and deputy chief medical officers from England, Scotland have looked at all the of the evidence both from the UK and internationally and the clear statement at the end of that was that a child missing out on their education is a much greater risk for them than Covid, for most children." She said that being out of school reduced children's health in the long term and the effects are worse for children from more deprived backgrounds."
Ms Harries said that Covid was generally a "mild disease for children." "We think that maybe for younger children they're less likely to get it and we know that they are much less likely to be hospitalised and very, very unlikely to die from the disease. So the balance is very much in favour of going to school."
Shadow education secretary Ms Green accused the Government of being “asleep at the wheel” on reopening of schools.
“The Government has to make the conditions suitable and safe for schools, for staff, for students and it’s been asleep at the wheel, she told ITV’s Good Morning Britain.
"It’s been not paying the attention that schools need to the details of how they are going to reopen, nor has it been out sending a strong and clear message to parents.”
She added: "In terms of making preparations for their return, while headteachers, principals and school staff have been working really hard over the last few weeks of the summer holidays to make the schools safe, I think the Government has been missing in action to be quite honest."