Local AM Paul Davies is calling for the permanent roll out of the enhanced train services running to and from Fishguard Harbour and Goodwick.
Launched in 2011, the additional services may cease in September due to doubts over Welsh Government funding.
Mr Davies said: “The additional rail services between Fishguard and Carmarthen have been a vital lifeline for people in Pembrokeshire. Doubt over the future of rail services between the towns will cause uncertainty for rail passengers, and I hope that the Minister makes a decision on the future of these services as soon as possible.”
Mr Davies also highlighted the importance of the services for ferry users. He added: "Additional capacity on this line has been welcomed by people in west Wales and it would be disappointing not only for rail users, but ferry users too if funding cannot be found to secure rail services along the line in the long term. "Previously, there were only two trains a day that corresponded with the ferry travelling to Rosslare, and one of those was scheduled for the early hours. These services mean that local residents and tourists can now travel on much more regular basis, which is great for the local economy.”