The INDIA bloc appears to be on the brink of unravelling as a third key leader, Bihar Chief Minister Nitish Kumar, appears likely to walk out. Sources said it is likely that Mr Kumar, in a last-minute U-turn, will partner the BJP in the coming Lok Sabha elections. Over the last two days, two key leaders -- Mamata Banerjee and Arvind Kejriwal -- have all but cut ties with INDIA bloc, ruling out any alliance with the Congress and saying they would go solo in Bengal and Punjab.