Irish Rail poured cold water on suggestions they could run train services through the night or at much later or earlier hours.
There have been growing calls for the rail operator to put on additional early or late trains to match service levels that are available in many EU countries.
However, in discussions with the National Transport Authority (NTA), Irish Rail said 24/7 operations would not be “viable irrespective of any level of funding” that was available.
A senior Irish Rail official said overnight gaps in service were a key time for maintenance works and if those hours were lost, “the infrastructure … could not be maintained to a safe standard”.
An email said: “The Irish Rail network does not allow for alternative routing of services unlike, for instance, certain parts of the Great Britain network where diversionary routes allow for longer operational days.”