Thousands of people took part in a 'Unite for Life' vigil organised by the Pro Life Campaign (PLC); Youth Defence; the Life Institute; and Family and Life in Dublin's Merrion Square this evening.
Gardaí put the numbers in attendance at over 25,000. Organisers say it was over 30,000.
Niamh Uí Bhriain of the Life Institute told the crowd their voice would not be silenced or ignored.
"And we are here today - and you have come not in your thousands, but in your tens of thousands, from the rebel homes of Kerry to the hills of Donegal, from every county and every part of Ireland and in the rain and snow and bitter cold - to tell Fine Gael that we are the pro-life majority, and that we will not accept abortion, not now, not ever, not in our country and not in our name."
She said Fine Gael had given a public commitment that they would not legalise abortion and were now denying that promise.
"But now they are reneging on that promise - now they want to legalise the killing of unborn children in this country, and it seems that's mostly at the behest of the Labour Party. Labour are now the cheerleaders for abortion in Ireland. They've described proposals to legalise abortion as a victory. We are here to tell them that there is no victory in the medieval and brutal solution of abortion. There is no victory in the death of a child - for mother or for baby."
The PLC said it was 'absolutely thrilled' with the turnout
"On a bitterly cold January afternoon when it was predicted that the weather would keep people away, Irish people turned out in many thousands to register their opposition to abortion legislation," PLC legal advisor Caroline Simons said.
Ms Simons told the crowd that claims by the Government that abortion was needed to treat threatened suicide in pregnancy had been "completely demolished at last week’s Oireachtas hearings on abortion".
"The psychiatrists who addressed the hearings were unanimous that abortion is not a treatment for suicidal ideation. There is no evidence whatever that suggests that abortion reduces the mental health risks of unwanted or mistimed pregnancy. But there is evidence that abortion increases the risk of future mental health problems for a significant number of women."
"If the Government legislates for abortion on the basis of the X case, this legislation would cure no woman of suicidal ideation, but it would put some women's lives at risk."
The international pro-choice movement, she said, viewed Ireland as a "jewel in the crown" of the pro-life movement.
"We are a beacon for the pro-life movement everywhere. Let’s fight to keep that light shining," she said.
Speaking at the vigil, Tyrone football manager Mickey Harte said he was "most concerned" that the Government proposes to legislate for abortion.
"Ireland is almost unique in the Western world in looking out for, and fully protecting, two patients during a pregnancy – a mother and her unborn child," he said. "We are here to oppose the unjust targeting of even one unborn child's life in circumstances that have nothing to do with genuine life-saving medical interventions".
Referring to the high standard of medical care in pregnancy, he said this high standard needs to "remain enshrined in our laws not undermined or diluted in any way".
"No individual or nation is perfect - we all have our faults and failings but when it comes to life before birth, we have a value system, an ethos which we should proudly share with the rest of the world.
And he urged those at the vigil to "keep in touch with Mr Kenny and Mr Gilmore and let them know repeatedly that the middle ground of Irish opinion opposes what they are proposing."
The anti-abortion “Vigil for life” has been planned since November.
Gardaí put the numbers attending a pro-choice counter-demonstration at 200.