 The representatives of the Ukrainian and Jewish populations boycotted the Congress, and the struggle between ethnic factions continued for several months.During the Russian civil war, the Soviet governments of Ukraine and Russia, prompted by the unrest in Bessarabia due to Romanian occupation, issued a joint ultimatum to Romania on May 1, 1919, demanding its withdrawal from Bessarabia, and the next day, Christian Rakovsky, the Chairman of the Ukrainian Soviet government, issued another ultimatum demanding the withdrawal of Romanian troops from Bukovina as well.The Red Army pushed the Romanians over the Dniester, and a Besarabian Soviet Republic was proclaimed.