At the time of the February Revolution of 1917, Vol'skii was in Tver, where he soon became a leading member of the local party. Together with his brother, he was elected to the Constituent Assembly as the representative of Tver Oblast. Following the Bolshevik seizure of power in 1917, he became active in the Socialist Revolutionary resistance to the Bolsheviks and became chairman of the Committee of Members of the Constituent Assembly who established themselves in Samara. The Bolsheviks declared him a counterrevolutionary, subject to immediate arrest. He went underground and the SR Central Committee sent him to the Volga region and to the Urals to attend the State Meeting in Ufa and organize an uprising against the Bolsheviks.