The intra-party struggles of late 1920s and early 1930s being a key factor in socio-economical and government and party development of the country, understanding modernity is impossible without understanding Soviet experience. The issue has been actualized by recent introduction of new sources into scientific use. Illegal prison press published by political prisoners in the USSR as Stalin's regime was enhancing and opposition was being eliminated, allows to trace alternative trajectories of political development of the Soviet state. Historiography on the intra-party struggles of late 1920s ? early 1930s is quite extensive. The issue has been studied both in Russia and abroad. However, a limited range of primary sources made it impossible to analyze discussions on ideological, economic, and political development of the Soviet Union as reflected in illegal prison press. In view of this, the authors consider it necessary to scrutinize materials of illegal press originating from the detention facility for political prisoners in Verkhneuralsk and to assess their gnoseological value for studying political struggles in the USSR in 1920s – 1930s. These materials have been found during the repair works in the Verkhneuralsk prison in January 2018. Magazines and records of political prisoners’ disputes were handwritten in notebooks and dated 1930-1933. Guided by the principles of historicism and objectivity and working within the methodological frameworks of ‘new political history,’ which pays special attention to political ideas and forms of political communication, the authors have made the following conclusions. (1) Recently found sources allow to clarify biographical data on inner-party opposition. (2) Introduction into scientific use of new documents and their comprehensive study can provide scholars with valuable information and flesh out intra-party struggles of 1920s – 1930s. (3) Analysis of political prisoners’ magazines and records provides details on everyday life in the ‘political isolator’ and its custodial system, and also gives some clues to alternative ways of Soviet development proposed by Stalin’s political opponents.