Assembly Speaker Ramendra Chandra Debnath told IANS that Sarkar submitted his resignation to him and he had accepted it.

Immediately after his resignation, Sarkar told the Communist Party of India-Marxist (CPI-M) that he would rejoin the party.

The development came amid reported efforts by the Trinamool Congress to split the Congress legislators' group.

A former veteran leader of the CPI-M and a former speaker of the Tripura assembly, Sarkar joined the Congress with his supporters in March 2010.

The 71-year-old Sarkar was elected to the assembly five times since 1978 from Teliamura constituency in west Tripura. But he was denied re-nomination by the CPI-M in 2008.

CPI-M state secretary Bijan Dhar told IANS: "Sarkar uphold political morality by joining his original party (CPI-M) instead of Trinamool."

In 2013, Sarkar was elected to the state assembly from Barjala constituency as a Congress candidate by a narrow margin.

"Of late the moves by Sudip Roy Barman and his followers to join the Trinamool Congress and the pulls and pressures from different factions had upset Sarkar," a close associate of Sarkar said.

Trinamool Congress Vice President Mukul Roy, who came here on a day's visit on Friday, met seven disgruntled Congress legislators including Sarkar -- just before the latter quit the assembly.

One of the seven, suspended Congress legislator Sudip Roy Barman, recently resigned from the post protesting against the Congress-Left alliance in the recent West Bengal assembly elections.

The Congress has 10 legislators in the 60-member Tripura assembly.

Meanwhile, Tripura Congress state president Birajit Sinha on Monday urged the Speaker to act under the anti-defection law against six Congress legislators: Sudip Roy Barman, Ashish Saha, Diba Chandra Hrangkhawl, Pranjit Singha Roy, Jitendra Sarkar and Biswabandhu Sen.