Carlow and Kilkenny have some of the most overcrowded classrooms in the country.
Figures show that, in both counties, more than 67 percent of primary school pupils are in classes of 25 or more.
The statistics say that Irish classrooms are now the second most overcrowded in Europe behind the UK.
The EU norm is 20 children per classroom.
The Irish National Teachers Organisation says it would take just €4.5 million euro to reduce class sizes across the country by one.
