The publication is devoted to the activities of L.D. Trotsky as the leader of the united and left opposition in the CPSU (b). The volume opens with an analysis of the reasons for Trotsky's departure from the official party course, leading, in his opinion, to the establishment in the USSR of the omnipotence of the top of the party apparatus headed by Stalin. Unlike their predecessors, the authors consider the speeches of Trotsky and his supporters in 1923 as the origin of opposition activities that did not result in real opposition.