On August 24, 1991, Gorbachev resigned as the general secretary the Central Committee of the Communist Party of the Soviet Union and dissolved all party units in the government. On the same day, the Supreme Soviet of the Ukrainian SSR passed a Declaration of Independence of Ukraine, calling for a national referendum on the independence of Ukraine from the Soviet Union. Five days later, the Supreme Soviet of the Soviet Union indefinitely suspended all CPSU activity on Soviet territory, effectively ending Communist rule in the Soviet Union and dissolving the only remaining unifying force in the country. Gorbachev established a State Council of the Soviet Union on 5 September, designed to bring him and the highest officials of the remaining republics into a collective leadership, able to appoint a premier of the Soviet Union; it never functioned properly, though Ivan Silayev de facto took the post through the Committee on the Operational Management of the Soviet Economy and the Inter-Republican Economic Committee and tried to form a government, though with rapidly shrinking powers.
The Soviet Union collapsed with dramatic speed in the last quarter of 1991. Ukraine was the first of 10 republics to secede from the Union between August and December, largely out of fear of another coup. By the end of September, Gorbachev no longer had the ability to influence events outside of Moscow. He was challenged even there by Yeltsin, who had begun taking over what remained of the Soviet government, including the Kremlin.
On 6 November, Yeltsin–who had by then taken over much of the Soviet government–issued a decree banning all Communist Party activities on Russian territory.
By November 7, 1991, most newspapers referred to the country as the 'former Soviet Union'.
The final round of the Soviet Union's collapse began on December 1, 1991. That day, a Ukrainian popular referendum resulted in 91 percent of Ukraine's voters voting to affirm the independence declaration passed in August and formally secede from the Union. The secession of Ukraine, long second only to Russia in economic and political power, ended any realistic chance of Gorbachev keeping the Soviet Union together even on a limited scale. The leaders of the three Slavic republics, Russia, Ukraine, and Belarus (formerly Byelorussia), agreed to discuss possible alternatives to the union. On December 8, the leaders of Russia, Ukraine, and Belarus secretly met in Belavezhskaya Pushcha, in western Belarus, and signed the Belavezha Accords, which proclaimed the Soviet Union had ceased to exist and announced formation of the Commonwealth of Independent States (CIS) as a looser association to take its place. They also invited other republics to join the CIS. Gorbachev called it an unconstitutional coup. However, by this time there was no longer any reasonable doubt that, as the preamble of the Accords put it, "the USSR, as a subject of international law and a geopolitical reality, is ceasing its existence".