Síle de Valera voters to give preference votes for Anti H-Block candidates in the 1981 general election, a comment which caused controversy. She held her Dáil seat until the 1981 general election, when the constituency boundaries were redrawn. She sought re-election in the new constituency of Dublin South. This caused tension within the local Fianna Fáil party, for one of the other candidates, Séamus Brennan, was a prominent opponent of Haughey. De Valera polled relatively well but narrowly failed to be elected, losing to another Fianna Fáil candidate, Niall Andrews. She contested the constituency again at the February 1982 general election, but saw
Éamon de Valera with the support of at least seven independents. The result was the First Inter-Party Government, with John A. Costello of Fine Gael as its compromise candidate for Taoiseach. Costello was duly nominated, consigning de Valera to opposition for the first time in 16 years. The following year, Costello declared Ireland as a republic, leaving partition as the most pressing political issue of the day. De Valera, now Leader of the Opposition, left the actual parliamentary practice of opposing the government to his deputy, Seán Lemass, and himself embarked on a world campaign to address the issue of partition. He visited