Former chief minister Gegong Apang on Sunday night met Governor V C Pandey and staked claim to form government in Arunachal Pradesh.
Thirty-eight Congress legislators, led by former home minister Kameng Dolo, revolted against Chief Minister Mukut Mithi to form the United Democratic Front and elected Apang as their leader.
The UDF claimed the support of 39 legislators, including Apang, who heads the opposition Arunachal Congress.
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 quit the Congress in 1996 to form the Arunachal Congress.
He was ousted from power by Mithi following elections in 1999, when the Congress secured an absolute majority by winning 59 of the 60 seats.
With the split, the Congress' strength has been reduced to just 21 legislators.
The battle is now likely to move to the floor of the assembly, with the governor asking Mithi to prove majority or resign.
Raj Bhawan sources in Itanagar, the state capital, said although Mithi has chosen to resign, Pande wants to adhere to the recommendations of the Sarkaria Commission, which says that the question of any party having gained a majority must be decided on the floor of the House.
Meanwhile, intelligence sources in Itanagar said at least 12 MLAs from the troubled districts of Tirap and Chnaglang resigned under pressure from the banned National Socialist Council of Nagalim (Isak-Muivah), which is allegedly helping the Bharatiya Janata Party oust the Congress.
With Inputs from G Vinayak in Guwahati
