Fidelma Healy Eames has become the first Fine Gael Senator and female government representative to confirm she will vote against the Government's proposals to legislate on abortion unless the suicide clause is removed.
The Galway based Senator informed the party leader and Fine Gael Headquarters of her decision last night.
She said, having reflected on the proposals contained in the Protection of Life in Pregnancy Bill, she cannot in conscience support it.
Senator Healy Eames said she is "deeply disappointed" that she finds herself having to vote against her party, for the first time, on the bill.
She said: "I've had to make this decision for myself. It is a very difficult decision, I'm now going to be voting against my party Fine Gael, it's the first time I've ever been in this situation and I'm very disappointed.
"I stood for election in 2011 on a pre-election promise, a pro-life pre-election promise, I'm not breaking that promise.
"The Government and the party has turned its back on it."