Kolkata: Fifteen guest lecturers of Jadavpur University's history evening course have threatened to stay away from teaching, invigilation and evaluation in protest against the removal of assistant professor Debajit Dutta, also the coordinator of evening courses, from exam duties.In a letter to the pro-VC Amitava Datta, they said if the decision against Debjit, taken on false allegations, was not revoked by Monday, they would not teach, evaluate or invigilate. Question paper moderation for semester exams, slated for June, are yet to be completed.TOI attempted to reach Amitava but he did not respond.The controller of exams removed Debjit from exam duties on May 16 reportedly following a letter from a few students, affiliated to TMCP, alleging malfunctioning in the exam process. "I wrote to the authorities on May 19, expressing my intention to quit as the course coordinator as it was insulting that without a proper probe, the controller removed me..." he said.The SFI JU arts unit also submitted a letter, alleging that a PG student was mentally harassed during his viva voce for speaking out against Debjit. tnn, who had barred some students from internal exams for low attendance. But Debjit said he was trying to implement university norm of 60% attendance. "The student could not perform at viva and he is accusing me of harassment," he said.