Decades of lax attitudes towards tackling deadly asbestos in schools is a national "scandal" threatening the health of school children, a wide-ranging investigation has found.
Education unions say examples of the problem in schools they have found have underlined "systematic failings" in the way it was dealt with by successive governments.
Whitehall had a "scandalous disregard for life" by permitting inadequate surveys and campaigning against compulsory detection that it said would help prevent future cases of asbestos cancer mesothelioma, according to the Joint Union Asbestos Committee (JUAC)
The committe's report said successive governments had failed to require schools to keep asbestos records and inform parents about the material in their child's school.
It said: "This has enabled the culprits to evade responsibility for asbestos exposure leading to mesothelioma, allowing them to escape with impunity.
"Nothing can be done to put right past asbestos exposure, but we must do more to protect future generations of school children and staff."
At the heart of the investigation is the story of one asbestos victim, Sarah Bowman, who developed the disease in her 40s - more than three decades after leaving Braincroft Primary and William Gladstone schools in the Brent area of London.
She was said to have been too ill to attend the National Union of Teachers (NUT) conference in Brighton this weekend where the report was presented.
The report found the risk to children - including Ms Bowman's son, who attended one of the schools several years later - was underestimated because risk assessments and tests were designed for adults working with asbestos, and not for long-term exposure of children who are known to be more vulnerable.
JUAC said government documents released under Freedom of Information rules suggested full and comprehensive new laws to reduce the risk of exposure to asbestos were dismissed by politicians on cost grounds.
Association of Teachers and Lecturers (ATL) general secretary, Mary Bousted, described the report as "shocking".
"It is outrageous that staff and pupils are still dying from being exposed to asbestos in schools," she said. "ATL has been campaigning about this for years. Action must be taken by the Government now."
Experts believe the government should do a comprehensive survey to establish which schools are affected, as currently the true scale of the problem is not known.
According to the Health and Safety Executive, more people in the UK die from the disease than in road accidents.
Asbestos campaigner Hank Roberts, presenting the report at the NUT conference, said: “Asbestos is giving death sentences as we sit here now to children for a terrible painful death later on.
“Next year there will be more of them and there will be more of them the year after that. Until all asbestos is removed, this will carry on."
The UK currently has the highest incidence of mesothelioma in the world and it is steadily increasing, according to the report.
A Department for Education spokesman said: "Nothing is more important than the health and safety of children and staff in our schools. Since 2010, billions has been invested to improve the condition of the school estate, with a further £23 billion on school buildings to come over this Parliament.
"This will help ensure asbestos is managed safely and that the amount in school buildings continues to reduce over time. We have also published new guidance on managing asbestos in schools, and have transformed the way in which we collect information on asbestos to better our understanding."