Zinoviev remained in opposition to Stalin throughout 1926 and 1927, resulting in his expulsion from the Central Committee in October 1927. When the United Opposition tried to organize independent demonstrations commemorating the 10th anniversary of the Bolshevik seizure of power in November 1927, the demonstrators were dispersed by force and Zinoviev and Trotsky were expelled from the Communist Party on 12 November. Their leading supporters, from Kamenev down, were expelled in December 1927 by the XVth Party Congress, which paved the way for mass expulsions of rank and file oppositionists as well as internal exile of opposition leaders in early 1928.