The Communist Party of India (Marxist) (abbreviated as CPI (M)) is a Marxist–Leninist political party in India. It is the largest communist party in India in terms of membership and electoral seats, and one of the six national parties of India. The party was founded through a splitting from the Communist Party of India in 1964; the CPI (M) quickly became the dominant faction.
The 34 years of CPI (M)-led Left Front rule in West Bengal was the longest-serving democratically elected communist-led government in the world. It emerged as the third largest party of the parliament in the 2004 national election. Presently, CPI (M) is a part of ruling alliances in two states - the LDF in Kerala, which it leads, and the SPA in Tamil Nadu.