Kolkata, June 1 : Shoumya Shubhra Roy, a senior counsel with the Calcutta High Court, has written to West Bengal Assembly Speaker Biman Bandopadhyay seeking immediate cancellation of Bayron Biswas' MLA post on grounds of betraying the voters of his constituency. Roy has also forwarded a copy of the letter to the office of the Election Commission of India (ECI). Biswas, who won the Assembly bypoll at Sagardighi in Murshidabad district just three months back as a Left Front-backed Congress candidate, jumped ship to the Trinamool Congress earlier this week. In the letter, Roy also said that if his plea for cancellation of Biswas' House membership is not accepted, he will approach the Calcutta High Court and file a PIL on this count. Roy argued that since the majority of the voters in Sagardighi elected Biswas as a Congress candidate, he betrayed their sentiments by joining the Trinamool and hence there is no ground for him to continue as an MLA. Meanwhile, Biswas has claimed that since he was the lone Congress legislator from the state, the anti-defection law will not be applicable in his case. "However, I am confident of my victory even if I have to resign and contest as a Trinamool candidate. I got elected because of my own charisma, and the Congress had no role to play in it," Biswas said. However, state Congress chief and veteran Lok Sabha MP Adhir Ranjan Chowdhury has thrown a counter challenge, saying, "If Biswas is so confident, he should resign immediately and face re-election at the earliest." /IANS