PM need not worry about Left parties, as we seen in last 3 years they just bark outside and raise the hands inside parlament to approve any bill. Since UPA in power no bills rejected due to Left parties oppsition. They were enjoying power without taking any ressponsibility. Any way all Left Parties was against india becoming Nuclear power. When NDA Govt detonated in Pokran Left was propagating their anger protest aginst India became Nuclear power.