The Minister for Education, Mr Dempsey, should introduce legislation to limit the weight of school books or face future litigation from adults suffering back pain, Fine Gael has said.
Mr David Stanton, the party's deputy spokesman on education, said research had shown that heavy schoolbags could lead to serious long-term back problems.
"One way of addressing this issue is to limit the size and weight of the books the children carry," he said.
"In the last number of years the trend has been to incorporate three years' work in one textbook. This has led to a dramatic increase in the weight of the textbooks being carried.
"The last thing we want to see is litigation from kids with bad backs. I think it is now time that the Minister took some action to limit the size and weight of these books as a health and safety matter for children." His comments follow calls from the employers' group, IBEC, for laptops to replace schoolbags within five years.
But a spokeswoman for the Department of Education said it was a matter for each school to choose measures that suited its individual needs.
"Positive action has been taken by many schools," she said. "At second level, actions taken by some schools consist of a range of measures, including the provision of lockers, the arrangement of the timetable into double-class periods, active liaison with parents and the co-ordination of homework by subject teachers."
Separately, the Labour Party has called on the Department of Education to take into account the financial impact on families and schools of changes to the curriculum.
"When changes are made to curricula in primary and secondary schools, it often means a big financial burden for families who have to buy the new schoolbooks for the new course. It also means books cannot be passed down from sibling to sibling when books for the old course become obsolete," said its spokeswoman, Ms Jan O'Sullivan.
"Such curricular changes also have ramifications for school budgets as teachers have to acquire new materials or equipment for the revised course. There is no financial support from the Department for such expense," she added.
The Department spokeswoman said curricular changes were made to keep pace with international best practice. Even if the curriculum remained static, schools are free to choose their preferred textbooks and may do so from year to year, she said.