A drafting error meant that the 4% cap could be doubled
The Dáil will try and pass legislation today to put rent certainty in place before the New Year.
Last night a problem emerged when an error was noticed that would have resulted in rent rises of 8%in the pressure zones of Dublin and Cork - rather than the 4% intended.
The Housing Minister Simon Coveney then moved an amendment to ensure the issue was fixed.
A drafting error meant that the 4% cap could be doubled immediately after the end of the current two-year rent freeze.
The error was spotted by Sinn Féin's Eoin Ó Broin, who called it a "major oversight".
Speaking on Thursday, Minister Coveney said they would double check the legislation overnight.
"If its helpful to the House we will look at the wording that we have and make sure that it is doing what we want it to do.
"We did put the amendment in place this evening when it was raised by opposition spokespeople - I'm happy to look at that again overnight to make sure that it's right, given the issues that people have raised".
Yesterday Fine Gael and Fianna Fail agreed to stick with a 4% rent gap, but to speed up their introduction in other urban and commuter areas.
The so-called rent 'pressure zones' look like being extended to include Limerick, Galway and Waterford cities in the New Year - as well as towns in Louth, Meath, Kildare and Wicklow.
But other opposition parties say it is a sell-out of renters.
People Before Profit deputy Richard Boyd Barrett said: "So it's more evictions, more affordability, more crisis in the rental sector as a result of a dirty deal between Fianna Fáil and Fine Gael".
Minister Coveney is under pressure to report a landlord's representative body to the competition authority.
The Irish Property Owners Association issued a statement saying they may implement a raft of new charges on tenants because of the new rent cap legislation.
They are threatening registration fees, car parking fees, withdrawing from state sponsored rental schemes and other charges on tenants.