The Left parties may lose heavily, and Mayawati's Bahujan Samaj Party (BSP) could emerge as a big gainer if snap polls are held now, according to a survey conducted by The Week/CVoter.While the UPA might secure 172-192 seats, the NDA's kitty can go up to 178-198, and the Third Front could gain 44-54 seats, the survey said.The strength of the Left parties in the 545-member Lok Sabha may drop to 38-48 seats from the present all-time best of 59 seats.BSP, which swept to power in the recent UP assembly polls belying all predictions, may see its numbers more than doubling from 18 to around 44-55 seats, the survey said.