In the 1967 Kerala Legislative Assembly election, his party contested as part of a seven-party alliance named Saptakakshi Munnani. E. M. S. Namboodiripad was sworn in as the Chief Minister but had to resign in 1969 due to internal dissensions within the alliance. Following this, the CPI exited from the coalition and constituted a mini-front which formed government with the external support from Indian National Congress. Achutha Menon was sworn in as Chief Minister on 1 November 1969. Noted as one of the best chief ministers Kerala has had, he continued till the dissolution of the third Kerala Legislative Assembly. The split in the Indian Socialist Party, a coalition partner and group politics within the Congress party led to the fall of his government on 1 August 1970.