CARS could be banned from Dublin city centre as early as next Christmas, a Dail committee has heard.
Transport Minister Noel Dempsey said that if a group set up to look at traffic in the city recommended that cars be removed from the streets he would be "guided" by their decision.
And the Dail Transport Committee also heard that unless commuters start switching to public transport, average speeds in the capital could fall to as low as 8kph by 2020 compared with 13kph today.
The minister said that between 1996 and 2006 the number of cars on the roads increased by 38pc from 382 to 528 cars per 1,000 adults, and that it would be "hard not to suspect that there will be further significant increases in car ownership ahead".
Chairman of the Transport Committee, Frank Fahey, said that "immediate traffic management arrangements to free Dublin from cars" needed to be implemented, including a ban on private cars.
"Before next Christmas we should be free of cars in Dublin city centre," he said.
Mr Dempsey said the expert group was finalising a traffic management plan. "If that requires getting rid of cars in the city I'll be guided by the group," he said.
But Fine Gael transport spokesman Fergus O'Dowd said introducing a ban before public transport alternatives were available was "gobbledegook".
"Until we have alternatives in place you can't ban them in the city centre, you're only going to move them onto other intersections," he said.
"To solve the problem you must have public transport in place. Until Metro is built, the best way to get people moving is to get more buses in."
A group, consisting of officials from the Dublin Transportation Office, the Railway Procurement Agency, Dublin City Council and other parties, is reviewing traffic arrangements in the city centre as major construction works for Metro North and Luas extensions are due to begin next year.
Cars could be restricted or banned from College Green, Westmoreland Street, O'Connell Bridge and Dame Street from the junction with South Great George's Street. The northbound lane of O'Connell Street and southbound on O'Connell Street from the Abbey Street junction would only be accessible to buses and taxis.
The group is expected to meet in May to discuss the issue.
In a separate development Mr Dempsey admitted that some Transport 21 projects were "slipping", but said they would be delivered on time once construction began.
The new Dublin Transportation Authority would require that "transport plans" be drawn up by developers who would not get planning unless they could show that adequate public transport would be provided.