Pepper fell from favor in 1928 as Joseph Stalin and Nikolai Bukharin parted company in the Communist Party of the Soviet Union, with Pepper's political views coming under criticism at both the 9th Enlarged Plenum of ECCI and the 6th World Congress of the Comintern. In 1929, Stalin repeated accusations against him at the ECCI Presidium and in May 1929 the Comintern sent an open letter to the American Communist Party relaying the news that the "Pepper case" would shortly be submitted to the disciplinary International Control Commission (ICC) of the Comintern The ICC returned its verdict in September 1929, confirming the accusations made against Pepper and removing him from all functions in the Communist International.