Deputies, elected in the rigged election, formed two legislative bodies – the People's Assembly of Western Ukraine, and the People's Assembly of Western Belorussia () on 22 October 1939, less than two weeks after the invasion. Meetings of these bodies took place respectively on 26–28 October 1939 in Lviv, and 28–30 October in Białystok. The Lviv meeting was opened by Ukrainian philology professor
Kyrylo Studynskyi, and the Białystok meeting by Belarusian peasant
Stsiapan Struh. Out of 926 members of the People's Assembly of Western Belorussia, there were 621 Belarusians, 127 Poles, 72 Jews, 43 Russians, 53 Ukrainians, and 10 from other nationalities. Both bodies supported the establishment of Soviet rule over the occupied territories, and issued official requests to the
Supreme Soviet, asking it for permission to join the already existing
Byelorussian Soviet Socialist Republic and
Ukrainian Soviet Socialist Republic. Nevertheless, the unification voting in the People's Assembly of Western Belorussia was not fully successful during the first attempt because 10
Lithuanians, who were elected to the People's Assembly of Western Belorussia, initially voted against the unification of Western Belorussia with Eastern Belorussia and explained that they instead want to unite with
Lithuania, thus the voting had to be repeated and eventually succeeded. Also, all real estate of landowners, churches and state officials, was confiscated without compensation (including buildings and animals). Banks and larger factories were nationalized, and 17 September was established as an official holiday. Meetings of both Assemblies were based on criticism of interbellum Poland, describing "exterminational policies of White Polish occupiers, bloodsuckers and landowners", who suppressed "Ukrainian and Belarusian masses". People's Assembly of Western Ukraine wrote an official letter, which was sent to the Belorussia Assembly. Among others, it said: "We were brothers in captivity and struggle against Polish masters. Now we have become brothers in freedom and happiness. Great Red Army, fulfilling the wishes of the mighty Soviet nations, has come here and for centuries freed us, Western Ukrainians and Western Belorussians, from suppression of Polish landowners and capitalists". On 1 November, the Supreme Soviet approved annexation of Western Ukraine, and on the next day, of Western Belorussia. On 14 November, the Supreme Soviet of Byelorussian Soviet Socialist Republic in
Minsk officially annexed former territories of northeastern Poland, without the area of
Wilno, which had been seized by Lithuania. On 15 November, the Supreme Soviet of Ukrainian Soviet Socialist Republic in
Kiev, annexed former southeastern Poland. On 29 November, the Supreme Soviet issued a decree upon which all inhabitants of Poland living in Western Ukraine and Western Belorussia became citizens of the Soviet Union. This decision had a far-reaching consequences, because now, the NKVD apparatus had legal reasons to arrest members of prewar political parties of Poland, accusing them of
Ex post facto anti-Soviet activity. Furthermore, the Supreme Soviet's decree resulted in massive draft into the Red Army. Polish historian
Rafal Wnuk estimates that 210 000 inhabitants of former eastern Poland, born in 1917, 1918, and 1919, ended up in the Red Army. After official annexation of Western Ukraine and Western Belorussia, both Assemblies were dissolved. ==See also==