Éamon Ó Cuív as been sacked from the Fianna Fáil front bench.
The party's leader Micheál Martin said Mr Ó Cuív’s membership of his front bench is “no longer tenable”.
It comes after he appeared along with a candidate who it was suggested the party would be running in the Northern Ireland local government elections next May.
Sorcha McAnespy was unveiled as Fianna Fáil’s historic first candidate in a local government election north in NI - however the party later denied it was happening.
A statement said: “Party Leader and Spokesperson on Northern Ireland Micheál Martin TD met last evening with Deputy Éamon Ó Cuív.
“During the course of that meeting, Deputy Ó Cuív made it clear that he was aware in advance of plans to hold an unauthorised launch of a candidate and agreed to participate in the event.
“In light of this information, regretfully, Deputy Ó Cuív’s continued membership of the party’s front bench is no longer tenable.
“His portfolio responsibilities will be reassigned in the time ahead.”
It comes after Senator Mark Daly was stripped of his duties as Fianna Fáil deputy leader in the Seanad for his role in the unsanctioned event in Omagh.