Cash-strapped universities are looking to international students to make up for funding gaps, according to the Director General of the Irish University Association (IUA).
The body has said a recent report shows there has been a 50% increase in student numbers in the seven universities it represents since 2000, and a further 20,000 extra students are likely in the next decade.
However, Jim Miley of the IUA has said that State funding has dropped from €9,000 per student ten years ago to just over €5,000 per student now.
Speaking on RTÉ's Today with Sean O'Rourke, he said that while the student registration fee has increased by about €2,000 in the same period, the rest of the gap has been made up by universities achieving efficiences and cost cutting.
Mr Miley said the number of foreign students in Irish universities has increased and now represents just over 10% of the total student population.
He said universities are using these students to help them balance their books.
Mr Miley said the body - which represents UCD, Trinity, DCU, UCC, NUIG, UL and Maynooth University - does not want to limit the number of students.
He said the Government has not acted on the Cassels Report, a 2016 report on third-level funding, which said an extra €600m was needed between universities and Institutes of Technology by 2021.
"To date, in real money terms, probably less than a quarter of that has been provided," he said.
He added there are three options for third level - either the student pays, or borrows to pay; the State pays; or alternatively we cannot cater for the volume coming.
Mr Miley said the IUA wants to sit down with the Government to "come up with a new partnership ... that will allow us to fix this problem".
He also said the system of third-level funding requires a more substantial change.
He said there are schools who have 100% of their students going to third level, and there are other schools where "maybe 10 or 15%" of students reach third level.
"As a society I don't think that is right. We think those students who have the ability but do not have the funds or the supports need to be supported.
"That requires the system to be changed. It requires more money overall but it also requires a change in how the money is allocated."
Mr Miley asked if the Government is saying it is acceptable that the children of well-off parents will be allowed access to third-level, which the State subsidises, while the children of parents who cannot afford it will not be able to go at all.