The average cost to parents of sending a student to second level is approximately €1,000, with the bill at primary level about half of this, a Labour Party survey has shown.
The survey of major retailers and specialist clothing stores, conducted earlier this month, shows that parents of children at second level are hardest hit.
According to the Labour Party, parents face paying approximately €1,020 on items such as school uniforms, shoes and runners, coats, sportswear, school books and school bags.
At primary level, a parent of a pupil in third class faces paying between €230-€272 on school clothes, €95 on school books, and €88 on administration costs.
However, not all parents have to pay for new uniforms and books every year and the costs can also vary considerably from school to school.
For example, if schools require a uniform with a school crest from a specialist retailer, this can add significantly to the final bill.
Presenting the research in Dublin yesterday, Labour's education spokeswoman Ms Jan O'Sullivan said the notion of free education was increasingly a myth for thousands of low and middle-income families.
Many were asked to pay what was "euphemistically called a voluntary contribution", she said.
"If schools were adequately resourced, such contributions would not be necessary," she said. "We know of parents who have to borrow to afford the costs of going back to school."
The Labour Party is calling for an increase of €100 in the back-to-school allowance at primary and secondary level for families on low incomes, and an extension of the income limits for the scheme.
It also called on the Government to increase funding for school book rental programmes, to extend the school meals scheme, to provide more information to families and schools about the supports available to them, and to deliver the proposed increase in child benefit.
Mr John White, acting general secretary of the ASTI, welcomed the proposals. Mr John Carr of the INTO said it was time for "the real cost" of sending children to school to be reflected in the grants paid to schools to provide books for needy children.