Thousands of students presenting Leaving Certificate results from previous years may face "significant issues" getting their desired college course if this year's calculated grades are significantly higher due to inflated results.
There are about 20,000 students who sat the Leaving Cert between 1985 and 2019 applying for college courses in this year's CAO process.
A senior academic source said universities have been inundated with calls from concerned students who fear they may now miss out.
It's after it emerged that teachers awarded more than double the number of top H1 grades in many subjects with the controversial calculated grades system introduced this year as a result of the coronavirus pandemic.
Politicians also raised the issue in the Dáil yesterday.
Green Party TD Marc Ó Cathasaigh said there is a "huge amount of worry" among students who sat the exam in 2019.
He gave the example of a constituent who has been trying to get into a competitive course for the last three years.
"She took 2019 to improve her HPAT [Health Professions Admissions Test] results, knows that her current aggregated score would be enough to get her into the course she's been trying to for three years and she's now worried sick she's going to miss the boat," he said.
"Students in this boat need to be looked after in the next round of CAO offers."
Around 10,000 of the 20,000 applicants sat exams last year.
Professor Pól Ó Dochartaigh, current chair of the CAO board and deputy president of NUI Galway said "there is a genuine fear" among students.
"We won't know specifically until we see the actual results next week, but if they end up being significantly higher than previous years, then students who sat the exams in previous years will face significant issues.
"Inflated grades, if they happen, would be justified if this year's cohort was actually significantly stronger than previous years' cohorts of students, but there has been no indication to date that that is the case.
"As such, if grades are inflated, they will not be credible."
A spokesperson for the Department of Education said it would not be appropriate for it to speculate on CAO points requirements this year.
Chief inspector with the department, Dr Harold Hislop, said students who sat the Leaving Cert last year and repeated in 2020 are likely to "do even better" due calculated grades.
"Some candidates who have results from 2019 are also, in fact, candidates in 2020. They are entitled to calculated grades and may do better or worse.
"However, given the grades arising, in some cases they are likely to do even better out of the calculated grades than they might have done in 2019."
Higher Education Minister Simon Harris announced 1,250 extra college places to help cope with demand.
He said 363 would be provided to degrees in health and education, while the remaining 900 would be divided up based on graduate intakes in the last few years.
Social Democrats TD Holly Cairns said that while the increase was welcome, it would present a challenge to colleges already struggling to adhere to social distancing.
"Will this result in more courses going online and will colleges be given the resources to accommodate these extra students," she said.