Universities say they need €234m from next year's Budget to help rebuild the system after years of cuts.
The Irish Universities Association (IUA) wants a significant step-up in State funding to cater for growing numbers of students and to carry out essential building and equipment upgrades.
It sets out its needs in a pre-Budget submission, warning the Government that the future competitiveness of the economy is at risk if universities don't get an "injection of essential resources".
The universities broke down their 2019 Budget requirements as a €90m increase in core funding, €40m to meet cost increases, such as national pay awards, and €104m for equipment and buildings improvements.
In its submission, the IUA points out that State funding per student in Irish universities has seen a "calamitous drop" to €4,397, half what it was in 2008.
Director general Jim Miley said the 2018 budget brought a modest increase in core funding for higher education, but, based on the analysis in the Cassells Report, the gap remained €550m.
The 2015 report concluded that the system needed an additional €600m a year in core grants by 2021, for day-to-day running costs, as well as €5.5bn for infrastructure by 2030.
The main funding options outlined by Cassells were either higher student fees, linked to a loan system, or a significant increase in State funding - and there is no appetite within Government for either.
Mr Miley said it was 725 days since the Cassells Report had been published and the sector could not "continue to deliver without the politicians of Ireland grasping the funding challenge for the university sector".
He said they wanted politicians across the Oireachtas to "stop kicking the can down the road", warning that failure to bridge the funding gap would "damage students' prospects and threaten the future competitiveness of the economy".
While the Cassells Report remains under consideration, the IUA wants Budget 2019 to demonstrate a clear Government commitment that the sector's calls for a significant increase in funding are being heeded.
According to the IUA, if the institutes of technology are included, the overall additional core funding requirement for higher education next year is about €220m, with further increases of €180m and €230m, needed in 2020 and 2021.
Mr Miley referred to the ongoing decline in the position of Irish universities in international rankings, which is blamed on the decade of cuts.
Concerns about funding and its impact on student experience and international rankings has prompted Ireland's largest university UCD to devise a range of measures, including an English Language Academy, to generate income to support the recruitment of 500 non-Exchequer-funded academics over the next five years.