In Ireland, there are several kinds of public inquiry. A Tribunal of Inquiry, often simply called a tribunal, is a powerful type of statutory inquiry whose procedures are governed by the Tribunals of Inquiry (Evidence) Act 1921 as amended. An Oireachtas inquiry is a less powerful non-statutory inquiry controlled directly by the Oireachtas (parliament). A 2013 proposal to strengthen the power of Oireachtas inquiries was defeated at a referendum. The Law Reform Commission published a report in 2005 examining the operation of public inquiries and recommending changes. A commission of investigation is a different form of inquiry, with evidence generally given in private; provided by the Commissions of Investigation Act 2004 to address scandals relating to medical care and child abuse.
Tribunals have been held to address many political controversies, increasing in frequency since the Beef Tribunal of the early 1990s. While they have been the subject of many dramatic revelations in Irish politics, they have also become known for running long beyond their intended length – the extreme case being the Mahon Tribunal (previously the Flood Tribunal) which began in 1997 and issued its final report in 2013.
The Tribunals of Inquiry (Evidence) Act, 1921 was enacted by the United Kingdom of Great Britain and Ireland before the setting up of the Irish Free State and as such remains in the Republic of Ireland. It has, however, been amended since by several Acts of the Oireachtas. The chair of the inquiry is mandated by the Oireachtas (following resolutions in both the Dáil and the Seanad) to carry out the inquiry into matters of urgent public importance by a Warrant of Appointment. The terms of reference of the inquiry are given as part of that warrant.