All-Russian Congress of the Communist Party of the Soviet Union

Fifteeth Congress

Resulted in the expulsion of the Left Opposition bloc in December 1927. In July 1928, Bukharin had secretly met with Kamenev, explaining his aversion and fear of Stalin and his policies. Kamenev wrote a report on the conversation. At this time neither the public nor most members of the Communist Party knew about the debate between the Left (Trotskyists) and the Right (Stalinists) in the Politburo. Left Oppositionists came into possession of the Kamenev report and circulated it widely in January 1929, when the Stalinists were still publicly denying differences within the right wing, although by this time Stalin's campaign to crush it was in full operation.