The Irish National Teacher's Organisation has said class sizes in primary schools are still far too big.
It comes in the wake of statistics from the Department of Education which show that the numbers of large classes in primary schools has dropped, with four out of five children now in classes of less than 30 pupils.
But the figures also show that around 100,000 children will still be in class rooms with more than 30 pupils this year.
General Secretary of the INTO, John Carr, has said it is unacceptable.
'We have a situation where the Government is claiming credit for a decrease when at the same time we have thousands of children in oversized classes,' he said.