Final answer:
Clement Attlee passionately condemned the Anglo-French and Israeli intervention during the Suez Crisis of 1956, opposing Hugh Gaitskell's initial conditional support for military action.
Step-by-step explanation:
During the Suez Crisis of 1956, it was Clement Attlee who passionately condemned the Anglo-French and Israeli military intervention to secure the Suez Canal. This contrasts with Hugh Gaitskell who initially informed Prime Minister Sir Anthony Eden that he would support military action against Egyptian leader Nasser if there was American backing, which ultimately there was not. The crisis, which involved the nationalization of the Suez Canal by Nasser and subsequent military responses by Israel, Britain, and France, led to significant international tension and the eventual withdrawal of the invasion forces following pressure from both the United States and Soviet Union.