More than three quarters of school staff have said they feel government guidelines on safety will be "impossible" or "difficult" to achieve when schools reopen tomorrow.
And an overwhelming 9 in 10 school staff lack confidence in the government's test and trace policy to ensure schools can open safely, while more than a third (35 per cent) have said they feel the government's approach to Covid safety in schools "won't work' and will leave them "at risk".
Unachievable: Distancing in schools won't happen, say 90% of teachers
Exclusive: 28% of teachers may flout test and trace
Back to school: 97% of schools plan to bring all pupils back full-time
In a Tes survey responded to by nearly 6,000 of school staff in England, 59 per cent said the government's guidelines on opening schools to all pupils tomorrow would be "difficult" to achieve, while another 17 per cent felt they would be "impossible".
"The guidance says children should try and stay over one-metre distance from each other but we just don’t have the indoor space to make this achievable," one respondent commented.
Another described how, while their school was putting each year group in "a pod", with tutor groups remaining in the same room each day while teachers moved classes, this did not prevent pupils from mixing at break and lunchtimes.
They added that some research from South Korea showing that 10 to 19 year-olds were "super spreaders" was "alarming", questioning the wisdom of "herding 30 into a room for whole days with no distancing and highly contaminated air even with windows and doors ajar".
Pupils don't understand social distancing or staying in a bubble
Early years practitioners commented that "young children need play and hands-on resources – it will be impossible to clean things between use", while those working in special schools commented that pupils "don't understand the concept of social distancing or keeping in a bubble, plus we have to do personal care".
Many raised the issue of how pupils would not be keeping to their bubbles while on public transport.
"The number of students and adults in my school daily amounts to 1,530, a ‘mass gathering’ by any standards," one respondent said.
"Students are with different teachers every hour, and different classmates according to their chosen options and ability set. So bubbles and social distancing are impossible.
"Students arrive crammed into a bus. They pour through the school gates like a river. If they had to stay 1 metre apart it would take hours to get them all into the building."
Government 'sees teachers as dispensable'
They added: "The government is burying its head in the sand because it has no answers and also because it sees teachers as dispensable."
However, one respondent said teachers and senior leaders needed to "show some initiative" in grappling with the problems.
The survey completed at the end of last term also revealed that 88 per cent of staff lacked confidence in the government's test and trace policy to ensure schools reopened safely.
Some pointed out "asymptomatic" pupils would make tracking cases difficult in practice.
And some drew attention to what they saw as the government's poor handling of the pandemic overall.
"I think government guidelines are just 'let's try and see measures' not followed by scientific advice," one respondent said.
35% said DfE school Covid safety guidance was risky and 'won't work'
The survey also found that more than a third – 35 per cent – of staff said they felt the government guidance for school openings would not work and would put them at risk.
"It is putting enormous responsibility on staff," said one respondent.
"Everyone is working extra hours and the constantly changing advice is extremely stressful. Our cleaning staff have expressed extreme anxiety at having the children's and staff's health in their hands," they added.
"The bubbles and staggered start/end/break times are unsustainable in the long run," one teacher said.
"We have a small site with narrow corridors. It is ludicrous to imagine that all of a year group will move from one room to another in the allocated three minutes.
'I wish they would stop the pretence that this will work'
"When do we clean a room between classes? The government has no idea how schools work in practice. I wish they would stop the pretence that this will work and be honest - they can't control it, but need people back as normal, so we have to accept the risks, illness and death that results."
Geoff Barton, general secretary of the Association of School and College Leaders, said: "The government guidance on the full reopening of schools is complex and challenging to implement, but we are deeply impressed by the fantastic work being done by leaders and their staff to put these measures in place, and to welcome back pupils.
"It is not possible to eliminate the risk of coronavirus entirely, but we know everything possible is being done to manage that risk and make the school environment as safe as it can be for staff and pupils.
'Vital that the government’s test and trace policy works'
"It is vital that the government’s test and trace policy works effectively in protecting the public and keeping schools open and we will be watching this closely."
Paul Whiteman, general secretary of the NAHT teaching union, said: “Inevitably, there will be anxieties. These are unprecedented and unusual times. Despite all the safety measures that are being put in place, anxiety is entirely understandable.
"It is essential that staff, leaders, parents and pupils all continue to work together to help ensure schools are as safe as possible in the circumstances. This will be a genuine team effort.
“Staff and leaders are dealing with a completely new world. So are parents and pupils. That is why we have been saying that the government needs to bring the maximum amount of clarity to proceedings.
"They haven’t done that in every case, by any means. It is very likely that government delays and uncertainty have contributed to the understandable anxiety that staff say they’re feeling.”
'Getting pupils back into classrooms a national priority'
A Department for Education spokesperson said: “Getting all children back into their classrooms full-time in September is a national priority because it is the best place for their education, development and wellbeing.
"This will be particularly important for disadvantaged children and those with special educational needs.
“We have always been clear in our guidance about the protective measures that schools should implement to reduce risks for staff and pupils as far as possible.
“Parents are becoming increasingly confident in their children returning to school, which is testament to the work of school staff across the country who are putting in place a range of protective measures to prepare to welcome back all pupils at the start of term.”