The National Bus and Rail union has criticised recent fare increases, saying that transport should be properly funded like any other public service.
Commuters are facing another price hike, with some fares going up from this weekend.
The National Transport Authority made the announcement earlier this week, saying, public transport companies need to raise revenue to survive.
Dermot O'Leary, General Secretary of the NBRU says it is up to the Government to fund the shortfall.
"The public service need to be funded properly and we're trying to encourage people to use public transport," he said.
"Increasing fairs has the opposite effect, and just increases car usage and that obviously just clogs up towns and cities.
"So we don't believe that the Government is pursuing the right policy in this matter at all."