In 1926, Naville married fellow surrealist Denise Lévy. That year he joined the French Communist Party (PCF), for which he managed the publication Clarté. He was a member of a delegation that visited Leon Trotsky in Moscow in 1927. He returned convinced by Trotsky’s arguments and was expelled from the Communist Party in 1928 for deviationism. From this point onwards, he and his wife participated in the life of the French Trotskyist extreme left and notably its publications. However, he became less and less convinced by Trotsky’s position, and broke with the group in 1939. He then organised attempts to create a Marxist left, devoid of Stalinist or Trotskyist trappings, through a publication called the Revue Internationale.