On Wednesday, 21 political parties have filed a review petition with the Supreme Court. They want the Election Commission to subject 50% of the Electronic Voting Machines to "random verification using the Voter Verifiable Paper Audit Trail (VVPAT)". This is meant to ensure that voting is above suspicion. The petition comes a day after the third phase of polling.

Earlier, the EC had told the apex court that there are practical difficulties involved. "Covering 50% of the EVMs for random verification shall extend the counting period to about six days," it said. Also, "counting those many VVPATs would require extensive training of officials. Huge capacity building should be executed before it's taken up."

The review petition comes in the wake of Akhilesh Yadav, Chandrababu Naidu, Mamata Banerjee and others alleging manipulations.