The Union of Students in Ireland has said a doubling of college registration fees to €3,000 would result in a large number of students dropping out of college.
The statement comes after Minister for Defence Tony Killeen refused to rule out substantial increases in registration fees in December's Budget.
USI President Gary Redmond said such an increase would make it very difficult for people to afford third-level education.
Speaking on RTÉ's Morning Ireland, NUI Galway President Jim Browne backed proposals to increase college registration fees.
Mr Browne said unfortunately Irish universities needed more funding to deal with the increased volume of students and to provide a good quality of education to those students.
He said any such increase should be accompanied by systems to support those unable to pay.
The USI, however, has said it will strenuously oppose any increases, which it claims would force a large number of students to drop out.
