Ireland had one of the lowest education budgets among developed nations as the boom years drew to a close, an independent study has revealed.

The think-tank report found just 4.7% of taxpayers' money was used in children's schooling in 2007 - compared to an average 6.2%.

The study, compiled by the Paris-based Organisation for Economic Co-operation and Development (OECD), said Ireland had the fourth lowest out of 31 countries.

Education at a Glance 2010, a report on national education, revealed that only the Czech Republic, Italy and Slovakia paid out less.

Sheila Nunan, general secretary of the Irish National Teachers' Organisation (INTO), said this was the reason Irish parents had to subsidise their children's schools.

She said: "Teachers and parents are rightly outraged when they see less than adequate funding for the education of young children being cut in order to rescue failed economic policies."

The Association of Secondary Teachers of Ireland (Asti) said: "This year's OECD's report - once again - confirms the importance of education in terms of keeping individuals in the labour force but also in terms of upgrading their employability and meeting the demand for skilled labour."

Both Asti and the INTO said the report confirmed Irish teachers were being paid below the OECD average.

The OECD said the impact of recession over the last three years showed the value of investing in education.

It said that during the economic downturn, young people with low levels of education were hard hit, with unemployment rates for early school leavers rising by about 5% in OECD countries between 2008 and 2009. The unemployment rate for graduates only increased by 2%, the report said.