Kolkata: On a day when Rahul Gandhi castigated West Bengal's Mamata Banerjee government over corruption, the ruling Trinamool Congress hit back at the Congress vice president for "changing his ideology like a T-shirt". Within hours of Gandhi's poll rallies in Howrah and North 24 Parganas district, Trinamool Rajya Sabha member Derek O'Brien mocked the Congress leader's ideology and played videos of two of his contrasting speeches -- one made in Kerala in February and other in Bengal earlier in the month. In his speech in Kerala where the Congress is pitted against the CPI-M, Gandhi is seen calling the Left's ideology "obsolete" while his address in Bengal where it has entered into an electoral understanding with the Marxists, Gandhi is seen asking people to vote for the "Left-Congress alliance and oust Mamata Banerjee". "For the Congress's wonder boy (Gandhi), ideology is like a T-shirt, you change it every day," said O'Brien. "At times, I wonder what will happen if the speech meant for Kerala gets interchanged with that meant for Bengal. Then there will be kushti (wrestling) in Bengal as well," he said. "There are several pages of research like those where both Congress and Left leaders have spoken against each other. Besides, one says it's an understanding, another says there is no alliance, yet another says it's an unofficial understanding," said O'Brien ridiculing the tie-up. Countering the Congress and the Left's claims of Prime Minister Narendra Modi and Mamata Banerjee being "two sides of the same coin", O'Brien displayed few pictures including those of CPI-M general secretary Sitaram Yechury greeting BJP patriarch L.K. Advani, union home minister and former BJP chief Rajnath Singh alongside Marxist veteran Prakash Karat among others. "Those who are saying about Modi and Mamata being two sides of the same coin, these pictures are for them," said O'Brien, referring to the state Congress on the day playing an old Mamata Banerjee TV interview where she called the BJP "a natural ally of the Trinamool". "There is no denying Trinamool was part of the NDA in 2001 but that was (Atal Bihari)Vajpayee's NDA and this NDA is vastly different. Moreover, 15 years have passed since then," added the Trinamool spokesperson.