BJP has a 'secret understanding' with Congress and both the parties have joined hands 'to swallow regional and other smaller parties', RJD supremo Lalu Prasad said today.

"Congress and BJP have secret understanding and they want to have a bipolar political system in India," Prasad told reporters.

He alleged that the two parties had joined hands 'to swallow the regional parties and other smaller groups'.

To buttress his points, Prasad said Congress had allegedly ensured 'clean chit' from CBI to Gujarat Chief Minister Narendra Modi in the Shoharabuddin encounter case.

"The two arrived at a secret deal and CBI netted a small chicken (a minister in Modi-led government), while it clears Modi of all charges. It says beyond doubt that the two big parties have a pact," he said.

Prasad slammed BJP General Secretary Anant Kumar for his reported claim that Lalu Prasad was not 'going to return to power in Bihar'.

"You know he is the same Anant Kumar who bowed to me after his comments in Lok Sabha. BJP does not have culture and it is a party of propaganda," he said.

Stating that the ruling BJP-JD(U) alliance in Bihar had "now gone into coma" with its defeat becoming imminent, he said all sections of people have decided to vote for the RJD-LJP combine for forming the next government.

"Voting for Congress will mean helping BJP+, he said.