"They brought Lalu out of jail and allied with him. Such a big sin. This is the politics of Congress," Modi told an election rally here in Kankurgachi area.
A special CBI court had convicted Prasad in the multi-crore fodder scam, but the Supreme Court granted him bail last December.
"They are bringing out people from jail and doing 'gathbandhan' (tie-up) and 'lathbandhan' (wrestling) with them. A game of wrestling and coalition is going on here," the Gujarat Chief Minister said.
Daring Congress, he said even if they brought out all those imprisoned, they were not going to win the Lok Sabha elections.
"I am telling this to the Congress people that even now one phase of election is left. Even if you bring out all people from jail then also you are not going to win the elections," he said.