He was a member of
Democratic Youth Federation of India (DYFI) and was taught by Dinesh Majumdar, the founder of DYFI. He worked at the grassroots level at Sealdah in
Kolkata and
Panihati in 24 Parganas. During the emergency period, he was elected to the Calcutta District Committee of DYFI. He served as the district secretary of the Calcutta District Committee of DYFI between 1982-1984. He became the Secretary of West Bengal State Committee of DYFI (1984-1991), and also as the All India Vice President of DYFI (1988-1991). He has been a member of the CPI(M) Kolkata District Committee and District Secretariat. He was elected to a member of CPI(M) West Bengal State Committee in 1990s and was included in the State Secretariat in 2012. He was elected to the CPI(M) Central Committee in 2018. He also represented CPI(M) at the Left Front W.B. State Committee and was a Working Committee member of
Centre of Indian Trade Unions (CITU). He was elected thrice from Ballygunge Assembly Constituency, part of South Kolkata Lok Sabha constituency. He was nominated to contest from Ballygunge in 1992 after the demise of respected CPI(M) leader Sachin Sen and won the support and confidence of the people. Deb also served as the Government Chief Whip in
West Bengal Legislative Assembly between 2003-2006. He is well known for his voice for the development of Ballygunge constituency and his contribution to the infrastructural development of the locality, such as the construction of elevated flyover from Paroma Island to Bridge No.4, Biresh Guha connector, construction of Gariahat Flyover, Lake Gardens Flyover, Bondel Gate Flyover, construction of 72 inches sewerage high capacity drainage system from
Bijon Setu to Rashbehari Connector, and also for modernization of the tram track from Ballygunge depot to Rashbehari crossing and Park Circus crossing, along with removal of soil wastes from Topsia Canal. He upgraded M. Memorial School (Urdu & Bengali Medium) at Topsia and Jagabandhu School at Shibtala to Madhyamik level. He established Wahed Memorial School at Broad Street and Shaheed-E-Yatan Ashfakullah Computer Training Centre. He commenced the Day-section of Naba Ballygunge Mahavidyalaya (formerly Charuchandra Evening College) and arranged Rs. 1 crore from Rajya Sabha Members’ Fund and MLA's fund for construction of new college building. He initiated the construction of new building for Muzaffar Ahmed School, and allocated Rs. 1 lac from Left MPs’ Development fund for the development of Humayun Kabir Institute. He created a playground at Garsa Abasan in Ward No. 90. He has also contributed a lot in pharma industry's field workers movement and he is the President of WBMSRU (West Bengal Medical And Sales Representatives'Union). He is the Working Committee member of FMRAI (Federation of Medical & Sales Representatives'Association of India). He was the General Secretary of AIPSO (All India Peace & Solidarity Organization) (Affiliated unit of World Peace Council) & Convenor, WB wing of AIPSO till 29 March 2013. Now he is the member of the Presidium of AIPSO, West Bengal State Committee and one of the Secretaries of AIPSO All India Committee. He had also contested
2004 Lok Sabha elections and
2009 Lok Sabha elections from the
Kolkata Dakshin Lok Sabha constituency but lost both times. He also unsuccessfully contested
Singur Assembly constituency in
2016 West Bengal Legislative Assembly election. He also contested
Rajya Sabha elections in 2018 against Congress leader
Abhishek Manu Singhvi. ==Personal life==