Addressing a press conference, CPI(M) state Secretary Bijan Dhar and party's Central Committee member Gautan Das termed the move as "separatist action".
"Our party has opposed the Citizenship (Amendment) Bill, 2016 and supports the Indira-Mujib pact with March 24, 1971, as a cutoff date to detect illegal infiltration into India from neighbouring Bangladesh," the CPI(M) leaders told reporters.
Indigenous People's Front of Tripura (IPFT), The Indigenous Nationalist Party of Tripura (INPT) and the National Conference of Tripura (NCT) yesterday announced the formation of All Tripura Indigenous Regional Parties Forum (ATIRPF) to oppose the Bill.
The CPI(M) leaders alleged the forum was unhappy with the restoration of peace after three decades of insurgency in the state was contained.
The TTAADC came into being in 1987 under Sixth Schedule of the Constitution to protect and safeguard the political, economic and cultural interests of the tribals, who constitute one-third of the population and the TTAADC constituted two-third of the state territory.