Transport Minister Leo Varadkar has said he has serious objections to proposals for multi-point tolls on the country's busiest road.
The minister said he was not fully convinced by a study carried out for the National Roads Authority (NRA), which recommended that five tolling points should be introduced across Dublin's M50 to combat congestion.
Mr Varadkar said: "We certainly don't think that serious congestion will return on the M50 in 2015. We think it will be further back than that.
"Also I have serious objections to multi-point tolling on the M50 because I think it will just displace traffic into other areas."
The NRA proposals could see motorists hit with 6.50 euro in tolls, which is more than double what they currently pay on the M50.
AA Ireland spokesman Conor Faughnan said the report from the NRA "belongs in the bin". He agreed with the transport minister, insisting that introducing more tolls would force motorists off the motorway and on to suburban roads, causing congestion there.
"This is an appalling idea that would do much more damage than good," Mr Faughnan said.
"On the one hand, you could apply so much punishment to drivers who want to use the M50 with tolls that are so high you could empty it and play golf on it. But the immediate effect would be re-congesting the suburbs."
He said residents in the likes of Blanchardstown, Castleknock and Chapelizod would be horrified at the prospect of congested traffic returning to their roads. "These suburbs are just beginning to breathe now that the M50 is finally doing the job it was built to do," Mr Faughnan said.
The AA spokesman said every toll that has been installed across the country has been regretted, because they only serve to divert traffic away from motorways. He said the one example of a road toll that works is the one at the Dublin Port Tunnel, which he claimed was used to deliberately deter cars from using it to clear the road for HGVs.