The Dáil has been told that passengers taking the new Luas Cross City line at rush hour would be "quicker walking" because of congestion in Dublin city centre.
The claim was made by Fianna Fáil's transport spokesman Robert Troy.
He said he took the Cross City line from Dawson Street to O'Connell Street this morning "in order to experience for myself the length of time".
"It took 20 minutes, I would have been quicker walking," he said.
"Coming back I took a taxi in order to be here for Question Time. [It took] 25 minutes.
"People are actually spending longer on public transport now than before this was introduced."
In response, Minister for Transport Shane Ross said he expected the traffic problems caused by congestion due to the new Luas line to be resolved "very, very quickly".
He said the volume of buses passing through College Green has been reduced by 20% and a proposal for a new College Green plaza is currently before An Bord Pleanála.
However, he said this would not happen until next May.
Mr Ross said there have been some teething problems, including getting people onto trams because of a lack of capacity.
"There have been problems and they are being addressed by the NTA (National Transport Authority) and will be resolved very, very shortly," he said.