While the Court unanimously found the relevant pension legislation unconstitutional, 5 of the 7 judges said that the meaning of family under Article 41 of the Constitution does not include both marital and non-marital families.

Chief Justice Donal O’Donnell in his ruling said the distinction in the welfare legislation between a married and unmarried couple was “arbitrary and capricious”.

In a separate concurring judgment, Mr Justice Séamus Woulfe said the differential treatment of a family not based on marriage amounts to discrimination which cannot be objectively justified.

Mr Justice Gerard Hogan also held the relevant provision is unconstitutional because of the automatic exclusion of cohabiting couples of long-standing. He said the reference to parents in Article 42 must include all parents even though this section is about education.