A total of 16,15,000 Voter Verifiable Paper Audit Trail (VVPAT) machines will be purchased to cover all polling stations. Several parties have been pressing for the use of these machines to ensure that the EVMs are not tampered with.
Sixteen parties had recently petitioned the EC to revert to the paper ballot system for greater transparency. The BSP, AAP and Congress had attacked the EC on the issue of alleged tampering of EVMs. PTI
Source : http://assamtribune.com