Employer groups have described proposed legislation to give workers on low-hour contracts better guarantees of so-called "banded hours" as "using a sledgehammer to crack a nut".
The warning came as the Joint Oireachtas Committee on Jobs, Enterprise and Innovation was hearing submissions on a Sinn Féin Private Members' Bill.
The bill proposes that workers who consistently worked hours above the hours prescribed in their contracts of employment should be entitled to seek revised contracts that accurately reflected their actual working hours.
Sinn Féin TD David Cullinane said the proposed legislation would provide more certainty for workers in precarious work or on low-hours contract, both in terms of their hours of work and in terms of their earnings and ability to secure loans.
A 2015 University of Limerick report estimated that 2.6% of the workforce were on low-hours or "if and when" contracts, which gave no guarantee of working hours, and reduced the ability of workers to secure loans or to plan family life.
However, the Irish Small and Medium Enterprises group queried the accuracy of data underpinning that report in relation to the prevalence of such contracts.
ISME CEO Neil McDonnell argued the bill would impose excessive obligations on employers to deliver hours which they could not necessarily guarantee.
He said before new legislation were introduced, evidence should be sought as to whether the current systems of enforcement of employment rights through the WRC were addressing the problems of low-hour employment.
ISME also noted that there was no "mutuality of obligation" in that only the employee would benefit from the legislation - as there was no provision for reverting to lower employment hours if trading conditions deteriorated.
Chambers Ireland Chief Executive Ian Talbot described the legislation as using a sledgehammer to crack a nut.
He warned it could have unintended consequences, as companies might reduce hours for staff in order to avoid long-term obligations to give workers more hours.
He described the proposed legislation as deeply flawed, unbalanced, unnecessary and disproportionate.
IBEC Director of Industrial Relations Maeve McElwee said that the proposed legislation would undermine secure employment rather than encouraging it - as companies would avoid giving workers additional hours in case that resulted in a long-term obligation to deliver those hours to staff.
She said some employers might also be more likely to contracting work out rather than giving staff additional hours.
She also criticised the fact that in order to avoid a liability to introduce banded hours on a long-term basis, an employer would have to prove that they were in severe financial difficulties - which could damage the credibility of the firm.