Proposals to ban passengers from some peak-time rail services unless they have pre-booked seats have been slammed as "absolutely unacceptable" by the chair of the Dáil's transport committee.
The claim emerged during a Prime Time broadcast this week which looked at the issue of overcrowding on Irish Rail services.
In the programme, Irish Rail chief executive Jim Meade said it is considering introducing restrictions on certain services to passengers who have booked ahead because of overcrowding.
These restrictions are already in place for certain high profile events, like All-Ireland finals.
The issue of overcrowding came into sharp focus in recent months.
On the day of the All-Ireland hurling final, the train from Westport was packed to the rafters.
Just days later, more rail travellers stood from Mayo to Dublin. This time, Post Malone performing in the RDS was held up as mitigation by Iarnród Éireann.
The issues have been raised by campaign group Rail Users Ireland, who describe the issues as "a common enough occurrence".
While Irish Rail wants to order 41 new carriages to mitigate the overcrowding issues, these will take two years to be delivered, a situation which has prompted Mr Meade to suggest that things may get worse before they improve.
Fergus O'Dowd, Louth TD and chair of the Oireachtas transport, tourism and sport committee, told RTÉ's Morning Ireland that he would be ordering Irish Rail bosses before the parliamentary committee within weeks to be quizzed about the plans.
He said suggestions that pre-booking could be required to get a spot on a train are "absolutely unacceptable".
While the government has vowed more investment in rail travel, the Fine Gael TD admitted that "there are problems because our economy is growing and it is creating significant stress, particularly on longer journeys".
Mr O’Dowd said the promised investment would “transformational over time” but added: “In the meantime, there is a lot of pain for a lot of people.”
Passenger numbers are continuing to grow on the Irish rail network.
Latest figures show a 5.3% increase in all Irish Rail passenger services - up to 47.9 million trips – a record number on the rail network.
Speaking on Prime Time, Mr Meade said, "I think we have to be honest with people and with the travelling public and say to them we will not have more capacity on the network for another two years.
Last month, Irish Rail launched a new website, peaktime.ie, in an attempt to try to persuade DART commuters to stagger morning rush-hour commuting journeys because of it overcrowding problems.
Senator Kevin Humphreys, Labour's transport spokesperson, has criticised the government for delays in expanding the rail fleet.
"Workers, parents and schoolchildren and are being crammed into these carriages at dangerous levels, with many parents with buggies simply unable to even get on," he said.
“Despite these repeated calls and media reports of the overcrowding situation, Minister Ross is continuing to stall the purchase of 41 additional carriages.
“We need to see real and genuine movement on this immediately, commuters deserve much more than what they are currently getting – which is less than nothing."