The USSR anti-religious campaign of 1928–1941 was a new phase of anti-religious persecution in the Soviet Union following the anti-religious campaign of 1921–1928. The campaign began in 1929, with the drafting of new legislation that severely prohibited religious activities and called for a heightened attack on religion in order to further disseminate atheism. This had been preceded in 1928 at the fifteenth party congress, where Joseph Stalin criticized the party for failure to produce more active and persuasive anti-religious propaganda. This new phase coincided with the beginning of the forced mass collectivization of agriculture and the nationalization of the few remaining private enterprises.