A group calling for the 8th amendment to be retained claim a vote for repeal "is a vote for abortion on demand".
The Pro Life Campaign also claim the 8th amendment has saved 100,000 lives.
In a statement the group says: "If repeal were to happen, it would mean that for the first time in our history, we would be withdrawing human rights from a vulnerable group of human beings instead of strengthening human rights protections.
"This move would have the effect of handing exclusive power to politicians on abortion and experience shows that politicians breach this trust."
It adds: "What the referendum to repeal the 8th amendment is concerned with is not any specific legislation that the Government may have in mind but instead it's about handing power to politicians to decide in future who should be deemed worthy of having their life protected in law and who should not."
They claim repealing the 8th "amounts to handing a blank cheque to politicians" to decide what our abortion laws should be.
"The reality is that, without the 8th amendment, unrestricted abortion on demand is a virtual certainty in the short to medium term."
The Government has said that it intends to hold a referendum on the 8th amendment at the end of May.
Children's Minister Katherine Zappone, Taoiseach Leo Varadkar and Health Minister Simon Harris announce plans for an 8th amendment referendum | Image via @campaignforleo on Twitter
The question put to people will be to repeal the 8th amendment, and insert an article into the Constitution - allowing the Oireachtas to legislate for abortion.
Speaking earlier this week, Taosieach Leo Varadkar said: "The question has to be a Yes or No one; do we reform our abortion laws or not?".
In advice published by the Attorney-General Seamus Wolfe, he suggested there is "no absolute certainty about the post-repeal landscape of rights."
But added: "If the amendment is adopted by the people, the Oireachtas would have an express power to legislate to regulate termination of pregnancy as it considers appropriate, in the same way as it legislates in every other area of policy.
"The insertion of the additional wording would bring greater constitutional certainty to the primary authority of the Oireachtas to make laws in this area, dealing with controversial social and medical matters.
The advice adds that: "Such an amendment would make it clear that it will be primarily a legislative function for the Oireachtas to determine how best to guarantee and balance proportionately the rights, interests and values that are engaged, in the interests of the common good."