The Republic’s National Transport Authority (NTA) is considering the outcome of a public consultation process, where a 20-minute delay to the new hourly Enterprise rail service is one of two options on the table.
The Irish Government announced €12.5 million (£10.6m) funding under the Shared Island initiative to improve rail connectivity on the island earlier this year.
The new hourly service is set to be launched in October, when Belfast Grand Central Station is expected to be open.
The plans include earlier morning trains departing Belfast and arriving into Dublin before 9am.
But that will double the frequency along the Belfast to Dublin corridor and the practicalities has created a timetabling dilemma in the Republic between local rail services and the Enterprise train.
As a result, the NTA instructed Irish Rail to launch a consultation on two timetable options.
The first option gives priority to the Dublin and Belfast trains.
But the second option would see local DART services take priority, meaning delays of around 20 minutes for the Enterprise in each direction.
Translink has already contacted stakeholders in the north, urging it to back option one.
In a Translink document seen by The Irish News, it said the second option “will impact passengers travelling on the Belfast to Dublin corridor, and on future investment on this route”.
It said the benefits to local DART services will be limited to timetabling, adding: “The economic benefits of prioritising intercity services are already well demonstrated across European and UK rail networks.”
Stormont’s Department for Infrastructure said it also backs the first option.
The issue was raised with Tánaiste Micheál Martin during Trade NI’s business event in Dublin on Tuesday evening.
In a statement on Wednesday, a spokesperson for the Irish Government said: “The NTA carried out a standard public consultation on new rail time tabling.
“One of the questions asked was whether people would like the existing timetable or have short delays to accommodate additional commuter trains from Drogheda.
“The overwhelming response was that the Enterprise timetable should not be delayed.
“The decision is now with the NTA but it’s expected that the sentiments of the consultation will be reflected in the outcome of the process.”
Retail NI chief executive Glyn Roberts, who raised the matter at Iveagh House on Tuesday evening, urged the NTA to prioritise the cross-border link.
“I think it’s completely counterproductive putting hundreds of millions into improving the service, improving the frequency, building a new transport hub, and then extending the service by another 20 minutes,” he said.
“We want to ensure there is a timely, accessible and frequent service, and adding 20 minutes to that clearly doesn’t help.”
Plans to upgrade the Enterprise service follows a record year for the service, with 1.17 million passengers using the train link in the 2023/24 financial year.
