His main contributions there were for legislation relating to overseas territories, and he also became the president of the General Council of Saint Pierre and Miquelon in 1956.

After receiving an elementary certificate, he became an assistant secretary for the Saint-Pierre town hall, resigning two years later to work for a commercial establishment.

[1] Following World War II, Claireaux entered politics by running for election to the constituent assembly, losing to Henri Debidour.

[1] Claireaux was opposed to the reduction of a subsidy to Saint Pierre and Miquelon in 1958 and gave several speeches on the topic, including getting into a heated exchange with Jacques Soustelle in November 1959, in which he claimed that it had devolved Saint Pierre to "a state bordering on poverty", with Soustelle calling Claireaux's statements as "allegations that do not correspond to reality.

"[1] In January 1960, he led a mass resignation of 10 of the 14 members of the General Council in protest and spoke before the French government of the financial situation.

"[1] Claireaux gave a speech in 1964 expressing sadness that Georges Pompidou's government did not provide subsidies for Saint Pierre, describing the territory as "a population of 5,000 inhabitants who have no other resources than a poor industry, that of fishing," calling it "a lack of a spirit of justice.

"[1] Back in Saint Pierre, Claireaux's candidate for the National Assembly was rejected for the first time in 1962, with the territory electing Albert Briand, a merchant and manager of the island's largest hotel and store.

Briand, who was unable to work with the Claireaux-supporting members of the General Council, resigned in June 1964 but was re-elected to the National Assembly two months later.