West Bengal Chief Minister Mamata Banerjee on Monday lashed out at the Election Commission, alleging that there were gross errors in the SIR exercise conducted so far in the state. Addressing a meeting of TMC's booth level agents at the Netaji Indoor Stadium here, Banerjee also alleged that the EC was appointing observers without informing the state govt, and working to foster the BJP's interests. The Election Commission is working only as per the directions of the BJP. There are gross errors in mapping of voters during the special intensive revision (SIR) exercise in the state, she alleged. The TMC supremo also asserted that cental officers who have been appointed micro observers for SIR hearings have little knowledge of the local language, and are unfit to conduct the verifications during the second phase of the ongoing revision exercise.