Abstract : The Glorious Thirties period in France is characterized by a progressive change in public policies. But this period is as well marked by a double process held by protester discourses : on the one hand, a politicisation of the urban question, and on the other hand, an urbanization of left-wing political positions. This thesis deal with the instrumentality of urban space in political ideology. What is the position of urban space in political ideology ? Which real part does it strategically take ? The simultaneous emergence of ideas such as "life surroundings", "everyday life", "participation", urban "auto-gestion", and considerations on "Urban Revolution" and "Class-struggle's urbanization" take part in the theoretical background of this double process. These ideas lead the city to become a stake for discourses and practices. Moreover, in Marxist and revolutionary ideology, the city is the key means for changing society. Among the leftists, some of the avant-gardes and the French "New Left", the dialectic between criticized space and saving space allows us to analyze the city status of an instrumental space.