René has had a long history in Seychellois politics. He worked with the British Labour Party until 1964, when he founded and led the Seychelles People's United Party (SPUP). The party originally adopted socialist policies, advocating the nationalization of key economic sectors, though it also espoused the views of the Catholic Church on social issues.
Prior to independence, the British government worked closely with René and other Seychellois politicians in formulating a new constitutional structure. They created an interim government consisting of a prime minister, a House Assembly, and a cabinet. Elections were held in 1974, with controversial results. The two political parties were the Seychelles Democratic Party (SDP), led by James Mancham, and the SPUP, led by René. Although the SDP's margin of victory was less than 2,000 votes, it received 13 of the total seats in the House Assembly.
During a 1975 constitutional conference in London, the two parties agreed to form a coalition government. The British then appointed a commission to investigate the electoral system, which the SPUP had claimed was unfair, and appointed Mancham to serve as interim prime minister. René assumed the post of minister of works and land development, a position he held from 1975 to 1977.
In 1976, the British and Seychellois leadership agreed to a new Constitution, which took effect on 29 June, with Mancham as president and René as prime minister. The new government lasted one year. In June 1977, SPUP supporters seized power in a bloody coup d'état while Mancham was in London. The SPUP then invited René to assume the presidency. Although René denied any involvement in the coup, it was widely assumed that he was behind the event.