The struggle of the working class against the capitalist class in order to be complete, i.e. a struggle of class against class, must foremost be revolutionary. The struggle should be against both individual capitalists and the capitalist class as a whole, and their power as well. The Communist Party, through its activity, organizes the workers and transforms the struggle against the exploiters into "whole class struggle, of a determined political party for definite political and socialist ideals"
Lenin argued: "....only the political party of the working class, the Communist Party can unite, educate and organize as the vanguard of the proletariat and the working class. This vanguard is capable alone to oppose the inevitable petty bourgeois' vacillations, the inevitable traditions and relapses of professional paucity or superstition within the proletariat and guide the action of the whole proletariat, namely to guide it politically and through the proletariat to lead the working masses"
It was a result of the Socialist Revolution's victory in Russia(1917) and its influence on the revolutionary workers' movement. The characterisation of the workers' parties as Communist has its roots in the "Union of Communists" and the Communist Manifesto by Marx-Engels.
Later, during the final decades of 19th century and in the early 20th century, the worker's parties were characterized as social-democratic or socialist, a characterization that expressed to a great extent prevailing reality in these parties. In April 1917, Lenin proposed the need to change the names of the workers' parties and to adopt the term communist and establish a new International.
In this direction the Communist International (3rd International) was founded in 1919. Over the years, under the influence of the new changes in the correlation of forces in the class struggle worldwide (the retreat of the revolutionary upsurge in the second half of the 1920s, World War II and the Nazi's attack against USSR in 1941, the "Cold War" and nuclear threat, as well as due to post-war capitalist development) new opportunist currents were formed, such as eurocommunism.
Opportunist currents also developed inside the Communist Parties of the socialist countries, with the 20th Congress of the CPSU (1956) as a milestone in this process. The transformation of the Communist Parties that exercised state power into treacherous parties of the counter-revolution was a catalyst for the deep, ideological-political and organizational crisis of the international communist movement.
It is not sufficient for the Communist Party today in order to be the vanguard of the working class to affirm its communist identity(title), to generally accept the Marxist-Leninist theory of scientific communism and recognize the vanguard role of working class. All the above are preconditions.
In order to be a vanguard, it must have a revolutionary political programme, it must have the ability to act in all conditions, namely in conditions of the movement's retreat or rise. It must develop and regenerate the ability to face the objective pressures that are formed by the negative correlation of forces in the class struggle.
A criterion for the character of a Communist Party is its programme and its political line: "To understand the meaning of the struggle of the parties, we shouldn't believe the words that are spoken, but we should study the history of the parties, probe the actions of a party and how they solve the different political issues, what is their stance towards the issues that affect the crucial interests of the different classes in the society..."
What is the main issue that determines the character of a party's programme, and what is the precondition for its revolutionary content?
The most important question that determines the revolutionary content of the programme of the communist party is the clarification of the revolution's character, i.e. the answer to the question: "Which contradiction will be solved by the impending social revolution, which class will take power?"
Based on this position, the line for the concentration of social forces is formed (motor forces), which have an objective interest in the revolution.