Francis went to Speaker T. Lokeswor's office in the morning to submit his resignation.
Later, he handed over his resignation from the party to Congress state unit President T.N. Haokip.
Francis told IANS that he will announce his next political move shortly. Speculation is rife that he will likely join the Bharatiya Janata Party.
People in his Tadubi constituency had held a meeting on Monday and decided not to allow him to campaign in their area unless he resigned from the party which the tribals dubbed as "anti-tribals".
Another former minister and sitting MLA N. Biren too resigned from the assembly and primary membership of the Congress. He is yet to join another party.
Haokip told IANS that he was bound to accept Francis' resignation, while admitting that the exit of senior party members was a setback for the ruling party.
The Congress is now left with 50 members in the 60-member assembly.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)