Ordinary duties and functions
The Constitution of Ireland provides for a parliamentary system of government, under which the role of the head of state is largely a ceremonial one. The President is formally one of three parts of the Oireachtas (national parliament), which also comprises Dáil Éireann (the house of representatives or lower house) and Seanad Éireann (the Senate or upper house).
Unlike most parliamentary republics, the President is not even the nominal chief executive. Rather, executive authority in Ireland is expressly vested in the Government (cabinet). The Government is obliged, however, to keep the President generally informed on matters of domestic and foreign policy. Most of the functions of the President may be carried out only in accordance with the strict instructions of the Constitution, or the binding "advice" of the Government. The President does, however, possess certain personal powers that may be exercised at his or her discretion.
The main functions are prescribed by the Constitution:
- Appoints the government
- The President formally appoints the Taoiseach (head of government) and other ministers, and accepts their resignations. The Taoiseach is appointed upon the nomination of the Dáil, and the President is required to appoint whomever the Dáil designates without the right to decline appointment. The remainder of the cabinet is appointed upon the nomination of the Taoiseach and approval of the Dáil; as with appointing the Taoiseach, the President is required to make the appointment without the right to appoint someone else. Ministers are dismissed on the advice of the Taoiseach and the Taoiseach must, unless there is a dissolution of the Dáil, resign upon losing the confidence of the house.
- Appoints the judiciary
- The President appoints the judges to all courts in Ireland, on the advice of the Government.
- Convenes and dissolves the Dáil
- This power is exercised on the advice of the Taoiseach; government or Dáil approval is not needed. The President may only refuse a dissolution when a Taoiseach has lost the confidence of the Dáil.
- Signs bills into law
- The President cannot veto a bill that the Dáil and the Seanad have adopted. However, he or she may refer it to the Supreme Court to test its constitutionality. If the Supreme Court upholds the bill, the President must sign it. If, however, it is found to be unconstitutional, the President will decline to give assent.
- Represents the state in foreign affairs
-  This power is exercised only on the advice of the Government. The President accredits ambassadors and receives the letters of credence of foreign diplomats. Ministers sign international treaties in the President's name. This role was not exercised by the President prior to the Republic of Ireland Act 1948
- Supreme Commander of the Defence Forces
-  This role is somewhat similar in statute to that of a commander-in-chief. An officer's commission is signed and sealed by the President. This is a nominal position, the powers of which are exercised on the advice of the Government. (See Minister for Defence.)
- Power of pardon
- The President, on the advice of the Government, has "the right of pardon and the power to commute or remit punishment". Pardon, for miscarriages of justice, has applied rarely: Thomas Quinn in 1940, Brady in 1943, and Nicky Kelly in 1992. The current procedure is specified by Section 7 of the Criminal Procedure Act, 1993. There were plans in 2005 for paramilitary "on the runs" to receive pardons as part of the Northern Ireland peace process, to supplement the 1998 early release of serving prisoners after the Good Friday Agreement. This was controversial and was soon abandoned along with similar British proposals. Power of commutation and remittance are not restricted to the President, though this was the case for death sentences handed down prior to the abolition of capital punishment.
Other functions specified by statute or otherwise include:
- The President may not leave the state without the consent of the Government.
- Every formal address or message "to the nation" or to either or both Houses of the Oireachtas must have prior approval of the Government. Other than on these two (quite rare) occasions, there is no limitation on the President's right to speak. While earlier presidents were exceptionally cautious in delivering speeches and on almost every occasion submitted them for vetting, Mary Robinson and Mary McAleese made much more use of their right to speak without government approval, with McAleese doing many live television and radio interviews. Nonetheless, by convention Presidents refrain from direct criticism of the Government.