The increasingly bitter battle between teachers and ministers over efforts to keep Scotland’s schools safe from coronavirus has intensified after a national survey revealed complaints that staff and pupils have been left to work in unclean, cold classrooms.

Some heads and deputes, meanwhile, suggested that Covid-19 transmission on campuses was not being reported, with responses also indicating teachers simply do not believe the Government position that schools do not contribute significantly to infections amongst staff and students.

Publication of the survey findings, which were gathered by the Educational Institute of Scotland (EIS), the country’s largest teaching union, comes as staff across the country declare formal disputes with employers which could lead to industrial action.

EIS members in Edinburgh have voted overwhelmingly to back the move, joining colleagues in Glasgow, Fife and West Dunbartonshire.

Disputes have been declared over claims that employers are failing to provide a secure working environment for staff in light of the continuing threat from the Covid-19 pandemic.

The EIS says current coronavirus measures in schools do not keep pupils or staff fully safe, and that there should be more remote teaching in place before and after the Christmas break.

However, new reports published by Public Health Scotland indicate that education staff and pupils have not been at an increased risk of severe Covid-19 as a result of being in school.

The latest EIS survey of primary and secondary teachers reveals a range of fears about the working environment, with concerns raised over cleanliness, temperatures in classrooms, mask wearing and adherence to social distancing guidelines.

One secondary school respondent told the EIS: “One third of pupils in the school are not wearing face coverings in corridors and communal areas.

“Approximately five per cent of S4-6 pupils are not wearing face coverings in the classroom.

“Windows are left opened to ventilate the classroom resulting in the room being cold.

“The school heating is normally switched off.

“During one school week before the October holiday, over 100 pupils were asked to self-isolate.

“A number of staff also tested positive for Covid and were off sick. Referred to a letter that there was no evidence of in-school transmission. Utter nonsense and frankly unacceptable.”

On the issue of cleanliness, one primary school respondent said: “I feel there has been a real failure to ensure that enhanced cleaning is done and the promised investment hasn’t materialised. We had a member of cleaning staff absent which meant six classrooms and the pupil toilets weren’t cleaned for two days. Teaching and support staff cleaned instead to keep ourselves and the children safe. This is a huge issue and, in my opinion, a massive failing on the part of our employer. Staff are buying their own wipes for wiping computers and teaching tables.”

The respondent added: “All of these things (plus many more) make for a stressful experience every day just now.”

Headteachers and deputes told the EIS they were doing their best to implement safety guidance but said there were just too many pupils in classrooms and communal areas.

Some suggested that transmission within their school was not being reported. One respondent said: “I cannot express how let down I feel. The lack of transparent reporting, the fact that schools are not talked about or level of cases actually shared within and across authorities is concerning.

“Local knowledge tells us that there are high levels of in-school transmission within the local area.

“To listen to the Deputy First Minister [John Swinney] talk about hardly any incidences in schools when we know otherwise is not acceptable.”

EIS General Secretary Larry Flanagan said: “The Scottish Government’s rejection of remote or blended learning for schools in areas with high rates of infection has increased the level of risk for pupils, teachers and their families. It is time for the Scottish Government to rethink this damaging policy.”

Separately, a high school principal teacher told the SSTA union: “Repeatedly the Scottish Government has let us down by expecting us to change our plans on their whim... insulted our understanding with regards to Covid-19 not being passed on at school... giving confusing advice regarding avoiding busy places but allowing schools to have a capacity of 1,000-plus people per day, not providing schools with enough PPE and cleaning supplies and more recently allowing schools to operate up until December 23.”

However, new Public Health Scotland reports suggest teachers and pupils are not at increased risk of severe coronavirus disease.

The PHS summary states: “Data shows that the occurrence of Covid-19 in school pupils and staff is consistent with the trends seen in the wider population during the autumn term, such as the rise and fall of infection rates across local authorities and that the proportion of education staff with antibodies for Covid-19 reflects that of the general adult population.

“New analysis also shows that teachers have not been at higher risk of hospitalisation due to Covid-19 than the general population since the return to school. The reports indicate that education staff and pupils have not been at an increased risk of severe Covid-19 by being in school.”

A Government spokesperson said: “We are grateful to all school staff for their dedication and hard work.

“Reports published today by Public Health Scotland on the impact of coronavirus on school staff and young people since August provide a range of new data that collectively shows that schools remain safe and underline the crucial health, wellbeing and educational benefits of children and young people being in school.”

A City of Edinburgh Council spokesman said it was aware of the dispute declaration and that it would continue discussions “with the EIS, our staff and other unions surrounding our commitment to keep our schools as safe as possible”.