 During the Dáil debate on the Emergency Powers Act 1939, Costello was highly critical of the Act's arrogation of powers, stating that He lost his seat at the general election of 1943, but regained it when de Valera called a snap election in 1944.From 1944 to 1948, he was the Fine Gael front-bench Spokesman on External Affairs.In 1948, Fianna Fáil had been in power for sixteen consecutive years and had been blamed for a downturn in the economy following World War II.