The Congress, which stood at the fourth position by winning 44 seats in the recent Maharashtra Assembly elections, now holds the key to formation of a 'non- BJP' government in the state.
The Shiv Sena, which is determined to form a government without its long-term ally BJP, on Monday said it is waiting for an official communication of support from both the Congress and NCP.
The BJP, which is the single largest party in the state, on Sunday decided against staking claim to form government for want of adequate numbers.
Governor Bhagat Singh Koshyari then invited the Shiv Sena, which has been at loggerheads with the BJP over sharing the chief minister's post.
The Sena is the second largest party in the 288-member House with only 56 MLAs after the BJP (105).
Given the stalemate between the two alliance partners, the role of the Congress and the NCP is crucial.
The NCP, which won 54 seats, 10 more than Congress in the state elections, said it had a pre-poll alliance with the grand old party, hence the decision on formation of a "non- BJP" government will be taken only after an official communication from the Sonia Gandhi-led party.
Senior Shiv Sena MLA Pratap Sarnaik said, "All the Sena legislators have signed our party's proposal to stake claim to form government. We are, however, waiting for an official communication from the NCP and Congress on extending support to us."