Chandrima Bhattacharya had recently replaced veteran organiser Subrata Bakshi as the party's state president. In a fresh blow to the Trinamool Congress, the party's Bengal unit chief Chandrima Bhattacharya has stepped down from the post. The development comes amid an ongoing rebellion in the party, both in Parliament and in Bengal.Former Bengal Chief Minister Mamata Banerjee seen with Chandrima Bhattacharya. (TMC/File )In her resignation letter, dated July 4, Bhattacharya said she was stepping down from the post she was being assigned to last month, and was disassociating herself from the TMC.Chandrima Bhattacharya had recently replaced veteran organiser Subrata Bakshi as the party's state president. The development had come at a crucial time – weeks after the TMC's crushing defeat at the BJP's hands in West Bengal Assembly elections, and a large section of the party MLAs revolting and joining hands to form another faction.Bhattacharya's move marks a significant setback for the TMC faction led by Mamata Banerjee. It was under the organisational overhaul by the chief minister that Bhattacharya was given the key post.Follow the latest breaking news, major developments and agenda-setting stories from India and around the world with the newsdesk at Hindustan Times. Operating round the clock, the desk brings together experienced editors, reporters and correspondents to deliver fast, accurate and contextual reporting across subjects that influence public policy, governance, business, society and international affairs.