The Council for Civil Liberties says the public is being misled over the need to change the constitutional right to citizenship.
If the June 11 referendum is passed, citizenship will only be granted to babies who have a parent who is already a citizen.
Minister for Justice, Michael McDowell, claims Ireland is vulnerable to abuse from citizenship tourists.
But the Director of the Irish Council for Civil Liberties, Aisling Reidy, said our constitution is far from unique, with 40 other common law countries around the world having the same citizenship rights for those born in the country.
Ms Reidy said that in the past Ireland has opted out of the chance to harmonise citizenship laws with the rest of the EU, and that there is no requirement for us to do so now.
She said that changing the constitution is the wrong approach and that Ireland needs a proper immigration policy in place before voting to change the constitution on this issue.