Kalikho Pul was sworn in as the new Chief Minister of Arunachal Pradesh late on Friday following 24 days of president's rule.
The central government on Wednesday had recommended that president's rule be removed from the state. However, the decision was kept on hold in the wake of the apex court's status quo order.
Governor J.P. Rajkhowa administered the oath of office and secrecy to the 47-year-old Pul at a ceremony at the Raj Bhavan.
The move witnessed the historic coalition government involving the Congress and the Bharatiya Janata Party (BJP). The BJP, which has 11 members in the 60-member House Arunachal assembly, is extending external support to Pul.
While former chief minister Mukut Mithi, also a Rajya Sabha member from Arunachal, was there in the ceremony, Nabam Tuki and his supporters did not attend the event.
However, Congress general secretary in-charge V. Narayanasamy called the formation of the new government as "highly illegal" and "unconstitutional" since Pul had not been voted as leader of the Congress Legislature Party.
The state BJP President Tai Tagak also accused the Congress leaders in New Delhi for the political chaos that forced the central government to declare the president's rule in the state.