A leading parents' group wants tax relief for parents who they say are "forced" to spend money on grinds because of "under performing " teachers.
The group representing parents in Catholic schools says the Department of Education has consistently failed to address the issue of under performing teachers .
Its spokeswoman, Ms Barbara Johnston said the parents of exam students were often left with no option but to pay out for grinds.
"We are told we have a right to free education. But tens of thousands of parents are paying €30 per hour or considerably more for grinds in order to give their children a fair chance. Why should these parents not be entitled to some form of tax relief?"
Ms Johnston claims grinds are now an integral part of the Irish education system but she says "people put their heads in the sand and pretend it is not happening".
Ms Johnston is chairperson of the Congress of Catholic Secondary School Parents' Association (CSPA) who will consider the demand for tax relief at its annual conference in Kilkenny this weekend.
The practice of getting extra tuition after school hours and at weekends has become such a widespread phenomenon in the State that a report three years ago by the OECD placed Irish students near the top of the league table when it came to getting grinds.
The most recent survey information suggests that about 70 per cent of Leaving Certificate students take grinds outside school hours.
The popularity of grind schools was also underlined by the finding that 49 per cent of Junior Certificate students attended grinds at least once a week.
Girls in single-sex schools were the most inclined to avail of extra tuition, with 79 per cent of them taking a grind.
The popularity of grinds, according to teachers, has increased greatly in the last decade, with some of the grind schools in Dublin becoming multi-million-pound businesses.
These schools provide weekly classes plus shorter "crash courses", when students cover a large amount of material intensively and receive extensive notes from teachers, many of them hand-picked from mainstream schools.
Teachers also give students lessons after hours in their homes.
Other teachers, however, greatly resent the grinds phenomenon, maintaining it undermines the very good work done by teachers in schools.
One leading grind schools says about 3,500 students attend its evening and Saturday grind classes while 3,000 attend Easter revision courses.