Passenger numbers at Portadown train station have dropped by 8,000 in the past 12 months.
Northern Ireland Railways have attempted to increase footfall at the county Armagh station but numbers continue to dwindle.
The figures were released to MLA Justin McNulty following a an Assembly question.
“The figures released only confirm what I and local people have been saying for months now, that Translink have chopped and changed their timetabling, at the expense of services to Newry, and as a result numbers of passengers using the trains to Belfast and Dublin are falling,” said Mr McNulty.
“The timetabling is a mess! We need to see train times which actually suit people trying to get to work in time for a 9am start.
“Quite simply the changes to timetabling in both Newry and Portadown are forcing people back into their cars.”
He added: “Poor timetabling, constant delays and service disruption coupled with lack of investment and a real commitment at ministerial level is damaging confidence in the service and this must stop.
“At a time when most other countries across the globe are investing in rail and at a time when the UK Government are investing in High Speed Rail our Executive is slashing rail services.
“People want a fast and reliable rail service and want to be able to use trains at an appropriate time.
“They want prompt services which will bring them to Dublin or Belfast in time for work and they want frequent services at all times of the day. I have been and will continue to highlight constant withdrawal of services and its impact locally.
“To lose 8,000 passengers in a year is a drop in numbers, even if there are over 700,000 using the service. It must and should justify a rethink in policy, this must happen and it must happen as a matter of urgency.”