In 1999, he embarked on a political career and was elected to Waterford County Council and Dungarvan Town Council. At the 2002 general election he was elected to Dáil Éireann for the first time, succeeding his father, former Minister for Agriculture Austin Deasy, who was retiring. He was appointed Spokesperson for Justice, Equality and Law Reform, by the new leader, Enda Kenny. He was sacked from the Fine Gael front bench in 2004, for smoking tobacco in the members bar at Leinster House, the seat of the Irish Parliament, just days after a nationwide ban on smoking in the workplace had come into effect. In October 2004, he failed to return to the front bench in the reshuffle, but was appointed Chairman of the Dáil European Union Affairs Committee.