In a major jolt to ruling Trinamool Congress in West Bengal, senior party leader Mukul Roy on Monday announced his resignation from the primary membership of the party. Announcing this at a press conference, the former Union Railway Minister also announced his resignation from the Rajya Sabha, CNN-News 18 said. Speaking to reporters, Mukul Roy said that he will resign from the party after the end of the Durga Puja. "With heavy heart I announce that I will quit from the Trinamool Congress," he said as per the channel. When asked the reason behind his resignation, Mukul Roy said he will reveal everything after some time, "I will reveal why I am resigning from the party, after Durga Puja," he was quoted as saying by ANI. Last Friday, state Chief Minister and party supremo Mamata Banerjee restructured the party's working committee and also removed the vice president post, which Mukul Roy was holding till recently. After this move, he simply remained a member of the party working committee. \u201cAs members of the working committee, we authorised her (Mamata Banerjee) to restructure the committee. And as a part of this restructuring, she has removed the post of the vice-president. So yes, Mukul Roy is no longer the vice-president but is still a member of the working committee. It isn\u2019t him alone, other vice-presidents too do not hold the post anymore,\u201d Trinamool spokesperson Partha Chatterjee was quoted as saying by Indian Express. #BREAKING - Will quit Trinamool after Durga Puja: Mamata's right-hand man Mukul Roy pic.twitter.com\/xz6na6oRal \u2014 News18 (@CNNnews18) September 25, 2017 \u201cBesides, it was felt that there are far more important posts and works \u2014 such as handling states which are to go to polls. Roy is the observer for Punjab,\u201d he told the paper further. The move by Mamata Banerjee is being seen as cutting down the wings of Mukul Roy within the party. He was earlier removed as in charge of the party in Tripura.