Today the Irish electorate is voting in a referendum to explicitly permit of same-sex marriage. If passed, the new Article 41.4, which would be the 34^th Amendment to the Constitution, will read: “Marriage may be contracted in accordance with law by two persons, without distinction as to their sex.”

Should the referendum be successful, Ireland will be the first country to introduce a constitutional guarantee to marriage equality by means of popular vote. Success is by no means guaranteed, although the polls suggest the ‘yes’ side has a steady lead. However, the campaign is taking its toll on people, with some canvassers reporting hostility on doorsteps, and the ‘no’ campaign erecting posters and campaigning in a way that have caused offence and distress to people in many ‘diverse’ family forms and, especially, those parenting children alone (including widows and widowers) or with an opposite-sex lover to whom they are not married.

That a profoundly challenging, robust and sometimes bizarre debate characteristic of Irish constitutional referenda would emerge was predictable. Given this, one might reasonably question the decision to hold a rights-conferring referendum with the attendant risk that the rights claim of the marginalized group would be denied. However, successive Irish governments have been of the view that a referendum is required to introduce same-sex marriage because the concept of marriage has traditionally been understood as being between one man and one woman. This was confirmed by the High Court in Zappone & Gilligan v Revenue Commissioners, which can be seen as the starting point of a long campaign leading to this referendum.

Although that case related squarely to same-sex marriage (the plaintiffs—two women—sought recognition of their Canadian marriage in Irish law), it also relates to the much longer-standing attempt to have Irish law recognise diverse family forms in a more general sense. For decades, the fact that the ‘constitutional family’ is the ‘family based on marriage’ has been the cause of some anxiety; it has clearly disadvantaged men who are not married to the women with whom they have had children, for example, as well as disadvantaging those children themselves by not including their families within the constitutional definition. In 2010 the Oireachtas [Irish parliament] introduced the Civil Partnership and Certain Rights and Obligations of Cohabitants Act, which established civil partnership for same-sex couples and introduced a legal regime for ‘qualified cohabitants’ related to, for example, inheritance and maintenance. This was unquestionably a significant step forward; for the first time it properly recognised in law a diversity of family forms in Ireland, ensuring that those who elected not to marry were not completely denied the protection of law. That said, marriage remained distinct; endowed with constitutional protection and considered the preeminent inter-personal intimate relationship.

Whatever the result of the marriage equality referendum, that will remain in the case. In fact, arguably a ‘yes’ vote on May 22^nd will strengthen marital family’s valorized position as “the natural primary and fundamental unit group of Society”, as the Constitution puts it. However, many in the ‘no’ campaign argue that allowing same-sex couples to marry will ‘redefine’ marriage and make a nonsense of this constitutional construction (see here for a discussion of these arguments). This results from an understanding of marriage as being a distinct institution because of the potential for procreation that is said to exist between a man and a woman and which does not exist in the same way between two persons of the same birth sex. Of course, there are many opposite-sex couples that also lack this potential for procreation (because of age, infertility, or permanent contraceptive decisions such as vasectomies) but, more importantly, it is already the case that the capacity to conceive a child together is not a requirement for marriage in Irish constitutional jurisprudence (Murray v Ireland [1985] I.R. 532). Thus, while this argument may have some instinctive attraction, it does not speak effectively to the antecedent understanding of marriage in the Irish Constitution.

The only change that a ‘yes’ vote in today’s referendum will render to that understanding is to expand it to two adults regardless of sex. The problematic hierarchy of family forms in Irish law will persist, leaving people who decide not to marry at a constitutional disadvantage. So too will a number of inequalities for LGBT persons in Ireland. However, the fact that marriage equality will not solve all ills does not mean that it will not solve some. In particular, in a system where the only route to formal constitutional change is a referendum of the People, the successful passage of the 34^th Amendment would send a powerful message of equality of esteem from the privileged majority who can currently marry to the marginalized minority who cannot.