In 1967 , after the defeat of the Congress Government , Jyoti Basu was sworn - in as the Deputy Chief Minister under the Chief Ministership of Ajoy Mukherjee .
In 1967 and 1969 , Basu became Deputy Chief Minister of West Bengal in the United Front governments .
In 1967 , after the defeat of the Congress Government , Basu   was sworn - in as the Deputy Chief Minister under the Chief Ministership of Ajoy Mukherjee .
In 1967 and 1969 , Basu became Deputy Chief Minister of West Bengal in the United Front governments .