The Prospective and Retrospective Effect of Judicial Decisions in Ireland

Abstract

This chapter examines the operation of the common law system in Ireland. The Republic of Ireland differs from many common law jurisdictions in that it has a written constitution which empowers judges to invalidate unconstitutional legislation. The importance of judicial decision-making in constitutional cases has influenced judicial practice more generally. Irish judges feel a constitutional duty to prioritise doing justice in each case. They have historically been less formalistic than judges in some common law jurisdictions. They follow precedent in a reasonably flexible way which allows the common law to develop. They have a creative role, although they exercise self-restraint in changing the law due to the separation of powers. This chapter considers whether the Irish legal system accepts prospective overruling or similar techniques designed to limit the retrospective effect of judicial decision-making. The question of retrospective effect has arisen most acutely in constitutional cases, where the courts find a statute to be invalid after it has been in force and people have relied on it. Two landmark cases limit the effects of a ruling of unconstitutionality by different means. Murphy v Attorney General states that an unconstitutional statute is void ab initio and that there should be redress in all but exceptional cases. A v Governor of Arbour Hill Prison precludes people who have been convicted under an unconstitutional statute and whose cases have reached finality from availing of the invalidity. The relationship between these authorities requires clarification, but they represent a functional equivalent of prospective overruling. If similar measures can apply when judges develop common law rules, then it appears that Irish law accepts prospective overruling.