Veteran CPI - M leader Khagen Das, convenor of Tripura's ruling Left Front and a former Lok Sabha and Rajya Sabha member, died in Kolkata following cardiac arrest on Sunday, party sources said.
Das, 80, a former Tripura minister, leaves behind his wife and two daughters.
His body was taken to Tripura capital Agartala in the evening.
It would be donated to the government - run Gobinda Ballav Panth Medical College and Hospital in Agartala on Monday.
Hundreds of Communist Party of India - Marxist (CPI - M) leaders and workers accompanied Das's body from the airport to the Tripura assembly, party offices and his residence at Ramnagar on the city outskirts.
"Das's body will be kept on Sunday at the party office for people to pay their last respects.
The body, as per his wish, will be donated to the Medical College and Hospital on Monday, " CPI - M Tripura State Secretary Bijan Dhar told reporters.
"As a mark of respect to the leader - - who joined the CPI - M in 1968 - the party flag will fly at half mast for two days and all party programmes remain suspended during this period.
"The announcement of names of party candidates for the February 18 Tripura Assembly elections would be done on Tuesday instead of Monday, as announced earlier. "
Das was in Kolkata to attend the three - day (January 19 - 21) Central Committee meeting of the CPI - M when he complained of chest pain early Sunday at the Tripura Bhavan, where he was put up.
"He expired within 10 minutes at 3. 35 a. m. before he was taken to a nearby private hospital, " a party leader said.
Das was one of the speakers on day two of the Central Committee session on Saturday.
Expressing shock and grief, the CPI - M decided to fly its flag at half mast as a "homage to this fighter for the cause of the working people".
Das was a Rajya Sabha member from 1998 to 2002, when he was elected to the Lok Sabha from Tripura West.
He retained the seat in 2004 and 2009.
When the CPI - M led Left Front government first came to power in Tripura in 1978, Das was a two - term (1978 to 1988) legislator in the Tripura Assembly from Majlishpur and served as the Health, Statistics and Revenue Minister in the state from 1983 to 1988.
A postgraduate from Calcutta University, he was the Political Secretary to then Tripura Chief Minister Dasaratha Deb from 1993 to 1998.
He was elected convenor of the Tripura Left Front in 2006 and served in that capacity till his death.
He was also a senior member of the party's Tripura State Secretariat.
A CPI - M Politburo statement said that Das had migrated from erstwhile East Pakistan (now Bangladesh) to Kolkata and did his schooling and college in Kolkata.
After completing his postgraduation from Calcutta University he worked briefly at the Kolkata Port Trust.
"Later on, he shifted to Agartala in the 1960s and worked as a schoolteacher.
It was during his involvement with the schoolteachers' movement that he was attracted to the party, " it added.
The statement said that Das was the founder - Secretary of the Democratic Youth Federation in Tripura.
He was elected to the CPI - M State Secretariat in 1994 and to the Central Committee at its 18th Congress in 2005.