Residents along one of the routes for the Swiftway 'bendy bus' scheme are concerned that their estates will become "car parks" for commuters using the service.
The scheme involves three routes: from Swords and Dublin Airport to the city centre; from Blanchardstown to UCD; and from Clongriffin to Tallaght.
The new system is designed to emulate light-rail systems, slashing commuting times into town - but at a much lower cost.
The National Transport Authority launched a public consultation process on the Swifway Bus Rapid Transit (BRT) Scheme.
In its submission on behalf of Swords residents, Fianna Fail said that commuter parking is a major concern for all estates along the preferred route.
The concern is that their estates will simply become "car parks all day long" for commuters who park and walk to the nearest Swiftway stop.
"The lack of a dedicated Swiftway stop around which a major car park could be built is a major flaw in this proposal," according to the document submitted by Senator Darragh O'Brien, and councillors Darragh Butler and Adrian Henchy.
"Metro North had a proposed car park stop at Lissenhall. We would predict that pay and display would have to be introduced to all estates along the Swiftway route which would prove a major inconvenience for residents," the document said.
Planning consent for the construction of Metro North was granted by An Bord Pleanala in October, 2010
However, in November 2011, the Government deferred the project pending the consideration of the next capital programme, which will be drawn up in 2015.
"We would like to state that we not necessarily against the concept of BRT/Swiftway and in fact we believe that we need improved transport solutions all across Dublin," it added.