The opposition parties, Telugu Desam, BJP and Congress on Saturday demanded that the bypoll to Tirupati(SC) Lok Sabha constituency be cancelled forthwith, alleging that the ruling YSR Congress instigated bogus voting on a large scale, particularly in the temple town Tirupati. The Election Commission has taken serious note of it and directed the Collectors of Chittoor and SPS Nellore districts to crack down on the bogus voters and ensure a fair poll, Chief Electoral Officer K Vijayanand said in a statement. State Director General of Police D G Sawang, however, claimed in a statement that the polling process was continuing in a peaceful atmosphere and everybody was exercising their franchise fearlessly .