[1] A member of the state committee of Communist Party of India (Marxist), Sur was the urban development minister in the first Left Front government in 1977.

An obstinate and proud man, the Rai Saheb continued to live at his home in East Pakistan until he was assassinated by the Pakistani Army in 1971.

Prasanta Sur had become the first Communist mayor of metropolis, and commenced the move that was aimed at reorienting the developmental drive of the civic body towards the mass of the people, especially the urban poor, and the refugees who had kept coming to the city and its surroundings, all the while.

A host of roads, bridges, and the Sealdah fly-over were constructed under him despite violent opposition by both factions of the Pradesh Congress (Subrata Mukherjee had then split from and was virtually at war with the Somen Mitra-led fraction).

He was assaulted in a brutish way—he carried the marks on his face well into his sunset years—when going on a house-to-house campaign in the Sealdah region, explaining to the people the need for the fly-over to be constructed.

The last journey from Alimuddin Street to NRS Hospital was attended by thousands of party workers and ordinary people paying their last salute to the strains of the "Communist Internationale".