Opinion polls for a number of years have consistently suggested that a strong majority of voters favour marriage equality and that the referendum on May 22 will be carried. However, multiple referendums in the past have seen strong early support collapse over the course of a campaign, leading to narrow victories in some cases and to defeats in others. This paper will examine the options for advocates of marriage equality in the event of a No vote in the forthcoming referendum. The picture is made more complex by the fact that the Constitution does not clearly prohibit marriage between two persons of the same sex, meaning that marriage equality could potentially be pursued via legislation or litigation. There is a strong argument that the Constitution permits legislation to be passed extending access to marriage to same-sex couples, and even an argument that the Constitution requires such an extension and renders current legislation invalid. Whether these arguments can be sustained in the aftermath of a No vote in the referendum will be explored.