New Delhi, Jun 14 (PTI): Efforts to form a grand 'secular' alliance against BJP in Bihar Assembly elections have suffered a setback with the Left parties reluctant to join such a formation and likely to fight as a separate bloc.

JD(U) sources said their proposal to the Left parties had so far not elicited any positive response and they have indicated that they would be going to the hustings as a separate formation.

Though the two major Left parties -- CPI and CPI(M) -- have weakened in Bihar over the years, the former continues to have some pockets of influence in the state where it was once the main opposition party.

The CPI(M-L) is currently the strongest of the Left parties, having support in parts of central Bihar and naxal- affected pockets of the state.

CPI(ML) Politburo member Prabhat Chaudhary said his party was unlikely to fight alongside JD(U)-RJD-Congress combine and was working for an alliance among the Left parties.

"We have been against the state government's policies and also those of Congress at the Centre. How we can support them in an alliance here?" he said.

A senior JD(U) leader rued that the Left parties often ended up being "on the wrong side" of political alignments and their decision against joining the alliance of Chief Minister Nitish Kumar and RJD chief Lalu Prasad would harm the "secular unity".

He, however, said they were still hopeful of a tie-up and leaders of the secular alliance were in touch with the Left parties.

Left parties together have a vote share of anywhere between 6 and 8 per cent which could play a significant role in a close contest.

BJP-led NDA and JD(U)-RJD combine are firming up their respective alliances as they work overtime to win power in the politically crucial state.

BJP has succeeded in winning over Mahadalit leader and former chief minister Jitan Ram Manjhi, while Lalu and Nitish have put their over two-decade long animosity behind to join hands to stop the saffron party from storming their citadel.