In the final year of the Soviet Union, negotiations were underway for a new treaty to restructure the country in to a loose confederation. Gorbachev invited the ASSRs to be participants in the drafting of the treaty, thereby recognizing them as equal to the union republics. However, a coup attempt in August 1991 derailed the negotiations and the union republics began to declare their independence throughout the year. The Soviet Union collapsed on 26 December 1991 and the position of the ASSRs became uncertain. By law, the ASSRs did not have the right to secede from the Soviet Union like the union republics did but the question of independence from Russia nevertheless became a topic of discussion in some of the ASSRs. The declarations of sovereignty adopted by the ASSRs were divided on the topic of secession. Some advocated the integrity of the Russian Federation, others were muted on the subject, while the Komi ASSR, Mari ASSR, and Tuvan ASSR reserved the right to self-determination. Yeltsin was an avid supporter of national sovereignty and recognized the independence of the union republics in what was called a "parade of sovereignties". In regards to the ASSRs, however, Yeltsin did not support secession and tried to prevent them from declaring independence. The Checheno-Ingush ASSR, led by Dzhokhar Dudayev, unilaterally declared independence on 1 November 1991 and Yeltsin would attempt to retake it on 11 December 1994, beginning the First Chechen War. When the Tatar ASSR held a referendum on whether to declare independence on 21 March 1992, he had the ballot declared illegal by the Constitutional Court.