The article explores the failed attempt of the all-Orthodox (Ecumenical) Council in the 1920–1930s through the prism of relations between the Constantinople Patriarchate, the Russian Church, and the Soviet government. In the situation of a strong Church discord in Russia, provoked by anti-religious policy of the Bolsheviks, the Patriarchate of Constantinople claimed the role of mediator between the Russian Church (“Tikhonovskaia”) and the Pro-Soviet Renovationist schism. The Ecumenical Patriarchate tried to collaborate with Soviet authorities in attempts to unify “Tikhonites” and renovators so that they could participate at the prospected Ecumenical Council. However, the transition of Russian Western European parishes to Constantinople in 1931 caused strong negative reaction from both the Russian Church and Soviet authorities. Finally, the Soviet leadership did not authorize a united delegation to take part at the Inter-Orthodox Pre-Council meeting (Prosynod). The absence of the Russian Church made both Prosynod and the Ecumenical Council impossible.