New laws that will demand unmarried fathers' names are included on their child's birth certificate will do little to protect their legal rights, campaigners have claimed.
Government plans, which have now been approved, will ensure for the first time that both parents' names must be automatically registered.
But Eamonn Quinn, of campaign group Unmarried and Separated Parents of Ireland, said the move does not go far enough because it fails to guarantee an unmarried man guardianship or access rights.
He added: "Getting the name on the birth certificate doesn't give a father automatic rights. The Government is only now doing something it should have done years and years ago, but even then we shouldn't be fooled into thinking fathers' rights are protected."
Cabinet ministers approved a memo from Social Protection Minister Joan Burton to change the Civil Registration Act 2004.
The amendment will address the current position whereby, in cases where the parents are not married to each other, a father is not required to give information on the registration of the birth, nor is the mother required to supply the father's details. When changed, the law will make this information compulsory - other than in exceptional circumstances.
Ms Burton said this reform was "long overdue". She added: "Ireland is one of the few countries where it is not the norm to have the father's name registered as a matter of course. This legislation will, when enacted, rectify that situation. It will give children vital information about their identity, and restate the significance of the role of the father in the life of the child."
Almost 40,000 children were born outside marriage in 2012, according to the Central Statistics Office.
Among those, 14,321 were born to parents who lived together. The remaining 25,344 were born to women who were not married nor shared a home with the father. Those men, according to Irish law, have no rights regarding their children.
Mr Quinn said the Government should put guidelines in place to improve fathers' legal rights, bringing them at least in line with the UK. He added: "Many a good man has gone to the grave because he has been denied basic rights regarding his own children."