After World War II, as a result of Polish population transfers, the native Polish population of Vilnius region was to a significant degree replaced with Poles from Belarus, as well as by Belarusians and Russians. This population did not have a history of strong Polish political identity. Also, a significant number of Lithuanians moved in the region. The beginnings of the autonomist movement are associated with the activities of Oleg Shenin, a member of the Central Committee of the Communist Party of the Soviet Union, aimed at the counteraction of the opposition of the republic against the Moscow rule. He is known to be instrumental in establishing similar ethnic-based subdivisions elsewhere in the collapsing Soviet Union: in Moldova and Transcaucasia. At the same time, Shenin threatened Lithuania that if it would not follow the Kremlin-established mechanism of secession, Lithuania might suffer territorial losses of the areas which the Soviet Union gained in 1939 after the Soviet invasion of Poland and later transferred to the Lithuanian SSR. He also threatened to defend "certain territories from the unilateral influence of separatist forces." These threats contributed greatly to the decision of the Lithuanian powers to ban the Polish autonomy.