A rise in the cost of rail travel between Belfast and Dublin has been criticised by the General Consumer Council.
The body says the flagship service is not delivering on its promises
The price hike, which is the second in the past year, means passengers on the Enterprise service are facing a 19% increase on the cost of a day return ticket since last year.
A day return ticket rises to £25, a £4 increase from July 2003, while the cost of a monthly return ticket rises by £2 to £33.
Mal McGreevy, general manager of rail services with Translink, said it was "a little bit misleading" to refer to a second price hike within a year.
"We normally review prices around July each year," he said.
"Last year, it was deferrable until August, so in reality this is the second price rise, but yes it's over a two year period."
"We have got to run a commercial business and make ends meet. We are facing increasing costs.
"But a £25 return fare to Dublin is probably one of the best value for money day fares within the British Isles."
Consumer Council chief executive Eleanor Gill said there needed to be "open and sustainable and transparent pricing policies".
"Unfortunately, on this occasion Translink have not come forward and justified to customers out there catching the train today why this increase is necessary."
She added: "We do not see the flagship service that was promised to us seven years ago meeting the service requirements.
"If today is an average day, by the published figures on an independent customer satisfaction agreed with Translink, 634 people leaving on the Enterprise will arrive late and over 1,000 will feel this is poor value for money."
The council has also raised concerns at the price rise ahead of a period of engineering works around Dublin which will disrupt the Enterprise service until May 2005.
"The council is working hard to highlight the positive aspects of public transport to encourage people to leave their cars at home, so this is particularly bad news and will damage consumer confidence," added Ms Gill.
"Hot on the heels of our neighbours in Dublin enjoying a new modern tram service for the 21st century, it seems like Northern Ireland passengers have to put up with second best."