Sinn Féin TD Peadar Tóibín said he will vote against legislation to allow for abortion but will not leave the party over the issue.
Mr Tóibín advocated a No vote in the referendum to repeal the Eighth Amendment and had sought a freedom of conscience vote for members of Sinn Féin.
At its ard fheis earlier this month, Sinn Féin declined to give a free vote and adopted a unified position to support legislation to allow for access to terminations within the first 12 weeks and beyond in certain circumstances.
Mr Tóibín said he fundamentally disagreed with the party on this issue but insisted it was the only matter he and Sinn Féin were at odds over.
Speaking on LMFM radio this morning, the Meath West TD said he would not be leaving the party but accepted he would lose the whip by voting against it.
The consequences for breaching the party position, he said, would be more severe than his previous three month suspension for voting against the Protection of Life During Pregnancy Act in 2013 but was unclear what sanction he would receive.
Mr Tóibín said: “Over the past three years, the party has changed its position significantly and it is one I have a radical difference of opinion on but it is only issue and I hope to remain with the party.”
He also confirmed he had made his position known to the party leadership in recent days.
Mr Tóibín's decision to stay comes days after Carol Nolan decided to resign from Sinn Féin over its refusal to give members a free vote on the abortion legislation.
Ms Nolan will now stand as an Independent in the next general election.
