The Mukut Mithi government in Arunachal Pradesh was reduced to a minority after 38 of the 59 ruling Congress MLAs, including 20 ministers, resigned and formed a new party.
They have formed a new party - United Democratic Front - and elected former chief minister Gegong Apang as their leader.
Apang, who ruled Arunachal Pradesh for 19 consecutive years from 1980 to 1999, was the lone non-Congress member in the 60-member assembly. He heads the Arunachal Congress, which he formed after breaking away from the Congress in 1996.
Mithi met Governor V C Pandey and submitted his resignation.
Later, Apang, along with some of the rebels, met the governor and staked claim to form the government.
Pandey is expected to give his decision on the claim on Monday.
It is believed that the rebellion has the tacit backing of the Bharatiya Janata Party, which has been trying hard to dislodge the Mukut Mithi government for the past one year.
Incidentally, Mithi had ousted Apang in a somewhat similar fashion in 1999.
