Iarnrod Eireann says it can't open Kishogue station, near Clondalkin, on the Kildare line from Heuston to Hazelhatch, because the road is not in place.
Construction on the access route was due to begin early in the New Year, with the hub to be open in the summer.
But an Iarnrod Eireann spokesman confirmed capital funding to build it is not now available so the station will remain closed.
"We did have capital funding to develop it but that has been reduced," he told the Herald.
Only two months ago rail chiefs had expected to be able to open the station next year.
The National Transport Authority (NTA) decided not to allocate the funding for the road, it has emerged.
Iarnrod Eireann said any new opening date "will be subject to funding availability".
It is another blow for commuters in the area who had been told originally that the station would be operational in 2011.
The building is located between Adamstown and Clondalkin and was due to be part of the Kildare Route Project that was completed in late 2009.
The Kildare rail line terminates at Heuston station and Iarnrod Eireann originally planned to link passengers with the proposed DART Underground project that has since been shelved.
Kishogue was built in the belief that a large number of homes would be developed nearby but this has not materialised.
Labour TD Robert Dowds has consistently called on the semi-State company to open the station, noting it is very close to multinational firms such as Pfizer and Microsoft.
He has branded it as "an appalling waste of taxpayers' money".
"Construction of Kishogue station was completed in December 2009, yet the station has yet to take a single passenger," Mr Dowds pointed out.
He said it is "totally unacceptable and a complete waste of taxpayers money" to have a newly constructed railway station lying idle.
His party colleague councillor Eamon Tuffy said he is "very disappointed" with the fresh delay.
He added that he has been told the NTA decided not to allocate the funding for the access road.