Zinoviev, Kamenev and their allies in the Bolshevik Central Committee argued that the Bolsheviks had no choice but to start negotiations since a railroad strike would cripple their government's ability to fight the forces that were still loyal to the overthrown Provisional Government.
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.
Kamenev and, indirectly, Zinoviev, were courted by Bukharin, then at the beginning of his short and ill-fated struggle with Stalin, in the summer of 1928, something that was soon reported to Stalin and used against Bukharin as proof of his factionalism.
Lev Borisovich Kamenev (Russian: Лев Борисович Каменев - his original family name was Rosenfeld, Розенфельд) (July 6 (old calendar) / July 18 (new calendar) 1883 - August 25, 1936) was a Bolshevik revolutionary and a prominent Soviet politician, an early member of the powerful Politburo.
In reaction, Kamenev joined the left opposition and soon became one of its prominent figures, arguing for the termination of the New Economic Policy and immediate industrialisation.
Kamenev was married to Leon Trotsky's sister, Olga Kameneva.