A conference to be held on Wednesday in Dublin by "Cherish" the national association of single-parent families will hear how non-married couples find themselves in a legal no-man's land.
The current law shows if the relationship between two people is not based on marriage, the law does not recognise that family as a family.
The law regards it as an assemblage of persons living in the same house.
Article 41 of the Constitution discriminates against non-married couples, unless couples choose to get married they have no legal protection.
Dr Fergus Ryan, a lecturer in family law at Trinity College says we are way behind other EU countries in this area.