Some pro-life commentators have voiced concern that abortion backers will infiltrate the gathering and that the assembly represents an abdication of parliament's responsibility.
An estimated 20,000-30,000 backers of legalized abortion marched in Dublin Sept. 24.
The Life Institute, which supports Ireland's pro-life law, said between 25,000 and 30,000 people attended the pro-life Rally for Life last year.
The pro-life group is campaigning with the hashtag "#RepealKills" in order to "bring the attention of the public to the fact that this means repealing the right to life of the preborn child, and that abortion campaigners are looking for abortion on demand."
"If we are going to debate abortion then we need to debate exactly what it does to mothers and babies," said Niamh Ui Bhriain, director of the Life Institute.
Ireland's abortion law is in the international focus. A leaked document attributed to billionaire George Soros' Open Society Foundations revealed funding for several pro-abortion groups in Ireland that are working collectively to repeal the pro-life amendment.
In the document's analysis, a win for legalized abortion in Ireland "could impact other strongly Catholic countries in Europe, such as Poland, and provide much needed proof that change is possible, even in highly conservative places."
Regional efforts within Ireland to oppose the Eighth Amendment have drawn limited support.
On Sept. 19 the Kildare County Council, by a vote of 18-9, rejected a motion supporting the repeal of the amendment and the institution of wider abortion services in Ireland.
Ui Bhriain said the vote is more reflective of what pro-life campaigners find.
"We're canvassing the nation on this issue, and the views of the ordinary voter are not being remotely reflected in the strident media campaign for repeal," she said.
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"There's a growing public awareness that beyond the 'repeal the eighth' slogan is the grim reality of abortion, and that abortion on demand is the aim of Irish abortion campaigners," she added. "This is not supported by most Irish people, who see the unborn child as a human being, and are increasingly uneasy with calls for abortion to be made freely available."
The scientific and media climate have also changed in pro-lifers' favor, according to Ui Bhriain.
"Science - and social media sharing - has revealed the humanity of the preborn baby, and we will make sure that the reality of slogans such as 'repeal' will be revealed in this debate"
Tracy Harkin of the group Every Life Counts noted the archbishop's support for the disabled and everyone who lives with life-limiting conditions, born and unborn.
"We are hearing a never-ending media clamor to have abortion legalized for preborn babies who are diagnosed with a life-limiting condition, and the archbishop's observation reminds us that if we truly believe in disability rights then we cannot argue for abortion on the basis on severe disability," Harkin said.
Harkin's daughter, Kathleen Rose, is a 9-year-old living with Trisomy 13, which is sometimes called a fatal abnormality. She said she was glad that Archbishop Martin spoke for her child's right to life and the right of "every child who is valuable and important despite their disability."