The fees issue "will not go away" and the Government faces hard decisions on third-level funding, according to the main author of the OECD review on higher education in the Republic.
Prof Michael Shattock, rapporteur for the OECD review team, signalled that the fees issue would have to be addressed if the State was to meet the ambitious targets set for it by the Government.
"If Ireland is going to realise its stated and wholly appropriate objectives for the contribution that higher education can make to the national economy, it is going to have to make some hard decisions," he said.
The landmark OECD report backed the return of fees but the Government has said this is off the political agenda "for the foreseeable future".
Prof Shattock said experience elsewhere showed that the fees issue could not be ducked, as "the investment required to fund mass higher education at an appropriate quality level is hard for governments to find against the competing interests of health" and other costs.
Prof Shattock was speaking at a conference on the future of the institute of technology sector at the Institute of Technology in Tralee, Co Kerry.
In his address, he also said that the Republic had failed to invest sufficiently in post-graduate research.
He also said research funding needed to be more concentrated if the Republic was to make an international impact.
He said the OECD team found a higher education system in Ireland that stood at the crossroads. The Government wanted a system in the top rank of the OECD but "we found that the system was cluttered with structural inhibitors which were likely to prevent the objective being realised."
Ireland, he said, was at a crossroads because the system had grown with "various ad-hoc policy initiatives, but there was no capacity for thinking about the system as a whole."
In her address, Dr Marion Coy, director of Galway-Mayo Institute of Technology, said several of the OECD review recommendations would undermine diversity, prevent innovation, damage regional development and perpetuate barriers to intellectual development.