The dramatic development came a day after they "impeached" Speaker Nabam Rebia in a make-shift "assembly" premises in a community hall.
Eleven BJP MLAs and two Independent MLAs joined hands with 20 Congress rebels to meet at a conference hall of a hotel in Itanagar as the Assembly premises have been sealed since Wednesday.
On Thursday, a "no confidence" motion moved by BJP MLAs and Independent MLAs was "adopted" with Deputy Speaker T Norbu Thongdok, who is also a rebel Congressman, in the Chair.
A total 33 members of the 60-member house, including 20 dissident Congress MLAs, later "elected" another dissident Congressman Kalikho Pul as the new "chief minister" of the state.
Chief Minister Nabam Tuki and his 26 supporting MLAs boycotted the proceedings terming them as "illegal and unconstitutional".
The chief minister later wrote to President Pranab Mukherjee and Prime Minister Narendra Modi seeking their intervention to "uphold" the Constitution in the face of the "unprecedented murder" of democracy and "bypassing" of a democratically-elected government by Governor Jyoti Prashad Rajkhowa.
Angry over the governor's action in calling a session of the assembly bypassing the government the the Congress has paralysed the Rajya Sabha for the last two days.
On Wednesday, a delegation led by Congress President Sonia Gandhi met President Mukherjee in Delhi and lodged a strong protest against Rajkhowa.
"It is clear that the BJP top leadership in connivance with some dissident Congress MLAs planned to destabilise the democratically-elected Congress Government in Arunachal Pradesh.
"This is obviously a pre-planned design involving the highest functionaries of the Central government in this unprincipled enterprise," the Congress chief told media persons after handing over a memorandum to the President.
Thursday’s "proceedings" were held in the new venue as the make-shift premises where Speaker Nabam Rebia was 'impeached' on Wednesday was vandalised by miscreants and the MLAs opposing Tuki were not allowed to enter the assembly premises by security forces.
As per directive of the speaker, the district administration has sealed the assembly premises since Wednesday.
The MLAs then with "due consent" from Governor J P Rajkhowa shifted the venue to the conference hall of in Naharlagun.
The "session", which was chaired by Deputy Speaker T Norbu Thongdok passed the motion by voice vote and signature consent by 33 members in the absence of 26 Congress MLAs including Tuki and his council of ministers.
Thongdok announced Pul as the "new Leader of the House" and said that the "proceedings" would be sent to the governor who would ask the new chief minister and his council of ministers to take the oath of office shortly.
Image: Chief Minister Nabam Tuki
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