The leading role of the party is a constitutional principle most common in communist states.
The leading role of the party was first enshrined in Article 126 of the Stalin Constitution, which described the Soviet Communist Party as "the vanguard of the working people in their struggle to strengthen and develop the socialist system and is the leading core of all organizations of the working people, both public and state."
The Communist Party, armed with Marxism–Leninism, determines the general perspectives of the development of society and the course of the home and foreign policy of the USSR, directs the great constructive work of the Soviet people, and imparts a planned, systematic and theoretically substantiated character to their struggle for the victory of communism.
On 15 March 1990 Article 6 was amended by the 3rd Extraordinary Congress of People's Deputies of the Soviet Union,[1] to read as follows: The Communist Party of the Soviet Union, other political parties as well as labor, youth and other public organisations and mass movements, through their representatives elected to the Councils of People's Deputies and in other forms participate in the policy-making of the Soviet state, in the management of state and public affairs.This move was introduced by Mikhail Gorbachev in tandem with the creation of the office of the president of the USSR (which he viewed largely as an office for himself), and as a means to formalize the transition to a multi-party political system.
[2] After the amending of Article 6 of the Constitution, the CPSU effectively lost its right to rule the Soviet Union's government apparatus; paving the way towards a multi-party democracy.