Fianna Fáil TD Eamon Ó Cuív said many of the party’s members support his opposition on the EU fiscal compact and will vote against it.
The Galway West TD said a lot of members are against the treaty because they have fears about its implications for the country’s financial future.
Mr Ó Cuív said he will continue to conduct interviews about the implications of the treaty for the future of the country, but that it was never his intention to canvas door-to-door against it.
Party leader Micheál Martin said his former deputy leader would not be taking part in referendum debates or joining the no side.
The divisions over-shadowed the launch of the Fianna Fáil campaign for a yes vote, during which Mr Martin acknowledged there was a “difference of opinion” within the party on the issue.
Asked if he was concerned that many party members would follow Mr Ó Cuív and vote no, he said every party has supporters who are for and against it.
“There is not a family in Ireland that doesn’t have different perspectives on this treaty,” Mr Martin said.
And he ruled out taking disciplinary action against Mr Ó Cuív. “I don’t need to assert my authority any further within the Fianna Fáil party, I’ve already done that.
“Eamon Ó Cuív, because of his views, has lost the deputy leadership of the party, he’s lost the position on the front bench.”
Mr Martin promised a positive campaign, but proceeded to accuse the Government of being “incompetent” in its handling of the economy. He said the coalition had been “too timid” in its approach to EU negotiations and its support for growth measures over austerity.
“There is a building, and I believe, irresistible, momentum towards a new growth agenda in Europe. Ireland must be more active in supporting this agenda.”
But he urged voters that the referendum was about the future of the country and “not about support for any party”.
Mr Martin said a yes vote on May 31 “is clearly the vote for less austerity”.
He insisted he was not a “Europhile”, as claimed by Mr Ó Cuív, and said he had been critical of the European response to the financial crisis.
Fianna Fáil said it would be spending between €120,000 and €150,000 on its campaign.
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