Fianna Fáil is to put down a private members motion in the Dáil later this evening, calling on the Government to reverse cuts to education made in the Budget.
The Government announced in December's Budget that from next September, career guidance teachers will be apart of the normal staffing allocation for secondary schools.
Up until now, there was a specific additional allocation for career guidance counsellors.
Fianna Fáil has described the move as an increase in class sizes through the back door and will result in 700 schools losing qualified guidance counsellors.
The party's education spokesperson, Brendan Smith, said that this amounts to another U-turn from the Government.
"The Fine Gael and Labour party, in their Programme for Government, stated that they would protect frontline services in education," he said.
"That's not happening."
"Guidance counsellors provide a critical service in encouraging students to choose appropriate education and career pathways and also offer advice and support relating to a range of personal issues.
"They are professionally trained to provide far more than career advice, with most guidance counsellors acting as a support to more vulnerable students.
"I am urging Minister Quinn to do the right thing and acknowledge that this is a particularly damaging mistake that must be reversed. Government TDs have the opportunity over the next two days to stand up for their local schools and ensure that current staffing levels and class sizes are maintained, and retain the essential guidance counsellor service."