Dasmunsi, who was in coma since 2008, passed away at a hospital here today. He was 72.
His body will be taken to the Congress headquarters on Akbar Road here, where top party leaders including its vice president Rahul Gandhi will pay their homage.
In her condolence message, Sonia Gandhi described Dasmunsi as a "devout" political activist and "one of the tallest" leaders of West Bengal. She said Dasmunsi served the party and government "illustriously".
"His work at the immense work at the grassroots would be remembered for posterity," she said.
Gandhi expressed solidarity with the leader's family, particularly his wife Deepa Dasmunsi, and supporters.
The former Union minister had suffered a stroke in 2008 and was hospitalised since then.