Executive power is exercised by the government which consists of no more than 15 cabinet ministers, inclusive of the Taoiseach and Tánaiste (deputy prime minister).
Legislative power is vested in the Oireachtas, the bicameral national parliament, which consists of Dáil Éireann, Seanad Éireann and the President of Ireland.
The judiciary is independent of the executive and the legislature. The head of the judiciary is the Chief Justice who presides over the Supreme Court.
While there are a number of political parties in the state, the political landscape has been dominated for decades by Fianna Fáil and Fine Gael, historically opposed and competing entities, which both occupy the traditional centre ground.
From the 1930s until 2011 they were the largest and second largest parties respectively.
Both parties trace their roots back to the opposing side of the civil war.
The Labour Party, historically the state's third political party has only ever been in power when in coalition with either of the two main parties.
In 2011 there was a major political realignment in Ireland, with Fine Gael becoming the largest party, Labour the second, and Fianna Fáil dropping to third following a collapse in support.