Both parties said electioneering will be at its peak during the exam season, causing hardship to students. BJP also said that the poll date would affect Tamil New Year festivities.
"Though the government had revised Tamil New Year from the Tamil month of Chithirai (April) to Thai (in January), a large section of people still celebrate it on Apr 14 and prepare for the festivities days ahead of it," BJP state president Pon Radhakrishnan said in a statement here.
The Apr 13 polling date would "affect" the festivities and its preparations, he said and demanded that elections be held in May.
He said a gap of one-month between polling and counting (May 13), during which electronic voting machines will be guarded in designated locations, will create "opportunities for mistakes," suggesting a possible tampering of EVMs.
CPI(M) state unit secretary G Ramakrishnan said around nine lakh students appearing for Class XII exams, scheduled from March 28-April 11, in Tamil Nadu and Puducherry will be affected due to campaigning.
"Further, teachers and government employees will also have to be employed for election duty. Therefore, the EC should revise the polling date keeping in mind the welfare of the students," he said in a statement.
He charged the Election Commission with not taking into account factors such as festivals and examinations before finalising the polling date.
Assembly elections for Tamil Nadu and Puducherry will be held on April 13 and the counting of votes will be taken up on May 13.