A Vanguard party is a political party of the popular working masses, that seeks to propagate Marxist ideas in an effort to create class consciousness that makes way for a socialist revolution, and to set up the dictatorship of the proletariat.
The idea of a vanguard party has caused some controversy in Marxist circles centered around the debate over whether workers need to be led to socialism by outside forces. Academic Marxology has held that Lenin's concept of a vanguard party signaled a change from Marx's focus on proletarian socialism to a revolution led by a tightly organized minority of intellectuals who would take socialism into the working class from outside.
“At this point, we wish to state only that the role of vanguard fighter can be fulfilled only by a party that is guided by the most advanced theory.” - Lenin, What Is To Be Done? – 1. Dogmatism And “Freedom of Criticism”