Here's your ten-point cheatsheet on this big story:
Sena chief Uddhav Thackeray pushed back his meeting with Maharashtra Governor Bhagat Singh Koshyari as the NCP left it to the Congress to take a call on whether to support a Sena-led government in Maharashtra. Sonia Gandhi met with top party leaders this morning and then called former chief ministers and others from Maharashtra at 4 pm to sound them out.
Uddhav Thackeray is tipped to be chief minister, with an NCP deputy, in a formula that has been in circulation over the weekend amid talks of a non-BJP alliance.
The Shiv Sena was on Sunday invited by the Maharashtra Governor to indicate "willingness and ability" to form government in the state after the BJP said it would not stake claim to power. The Sena has to show numbers in its favour by this evening and it needs the support of the NCP and the Congress to do so.
The Shiv Sena pulled out its minister from the central government to set the stage for talks. "Shiv Sena is on the side of truth. Why stay in the government in Delhi in such a false environment," tweeted Arvind Sawant after quitting as Minister for Heavy Industries and Public Enterprises.
The NCP had asked the Sena to quit the NDA for any possibility of an alliance between the rivals to come into play. Sharad Pawar held a meeting of the NCP core committee. "Whatever decision is to be taken will be taken only after discussions with the Congress," said Mr Pawar before the meeting. An NCP leader repeated it after the meeting.
Sonia Gandhi had earlier ruled out supporting the Shiv Sena. But under pressure from its Maharashtra leaders, the party seems to be wavering. The party is also undecided on whether to back a Sena government from outside or as part of it.
Caretaker Chief Minister Devendra Fadnavis of the BJP resigned on Friday. On Saturday, as the term of the Maharashtra legislative assembly ended without any resolution, Governor Koshyari invited the BJP to form government. "If the Shiv Sena wants to insult the mandate of the people and form government with the support of the NCP and Congress, they have our best wishes," the BJP said after informing the Governor that it would not stake claim to power.
The BJP and the Sena, long-term allies for around 30 years, won a majority together in last month's Maharashtra elections. The BJP won 105 seats and the Sena 56, which placed them comfortably ahead of the majority mark of 145 in the 288-member assembly. However, the Sena demanded a guarantee, in writing, that it would have the chief minister's post for half the term and an equal share in ministries, in what it called a "50:50" deal discussed with BJP chief Amit Shah. As Devendra Fadnavis denied any such deal, the Sena's attacks on the BJP became more and more vitriolic.
In an editorial in Saamana, the party mouthpiece, the Sena had said last week: "With 54 MLAs of NCP, 44 Cong MLAs and few independents, we can reach majority. The Sena can present its own Chief Minister and for that, three parties with independent ideology should form policies which are acceptable to all".
After the Governor's invite, the Sena moved its legislators to a resort in Madh Island, two hours away from Mumbai. "We believe that the BJP will try all means to induce our MLAs," said Sanjay Raut.