Transport Minister Shane Ross has ruled out free public transport for all to help tackle climate change claiming it would be far too costly.
Mr Ross said around €600 million is collected in fares each year and this would have to be made up by the taxpayer if public transport was to be provided for free.
He said that figure would not factor in the cost of providing the additional fleet, depots and drivers that would be needed to meet the "substantial increase in passenger numbers" if fares were eliminated.
"In summary, introducing free public transport for all users would require substantial additional funding by the taxpayer or from other sources."
Solidarity-BPB TD, Ruth Coppinger said free public transport has been rolled out in 100 cities in Luxembourg and pointed to the fact that 52% of transport emissions come from private cars while just 4% comes from public transport.
"Dublin is now the slowest moving city in Europe. This will benefit people's lives, as well as the environment," she said.
Separately, Mr Ross said he will seek a meeting with his British counterpart over the "peculiar" ownership structure of Rosslare port as soon as the Government is formed in the UK.
Minister Ross has previously come under fire for failing to bring Rosslare harbour — which is owned by a British company set up under UK statute — under full control of the State
Fianna Fáil's Mary Butler raised the complex ownership issue in the Dáil and warned that the port "wrong-headed to leave it in control of a foreign nation" given the threat Brexit now poses.
The port was established under the Rosslare Fishguard Harbours Company 1898 by UK statutory instrument.
Under this act, the British government delegated control of Rosslare to Iarnróid Eireann and Fishguard in Wales comes under the control of Stena Line.
Pressed on the issue in the Dáil, Mr Ross said he would be "happy" to get his officials to look at it with a view to introducing legislation here and in the UK.
He agreed that the ownership structure is "peculiar" and "archaic" but claimed that it doesn't seem to be impacting on the working of the port.
But Ms Butler said: "Given the port's strategic importance to the island of Ireland, it would be wrong to leave it in the control of a foreign nation, particularly as that nation prepares to exit the European Union. I acknowledge that this is a very complex issue, but it is vital that Ireland regains control of this port in order to ensure it plays its role in preserving Ireland's export capacity."