The latest updates on this big story are:
"We respect the Supreme Court judgment. Democracy must be followed," Uddhav Thackeray said in an online address, announcing that he was quitting as Chief Minister as well as a member of the Maharashtra Legislative Council. He then left for the Governor's residence to hand over his resignation.
The Chief Minister and his team, reduced to just about 15 MLAs, had asked the Supreme Court to stop the floor test called today by the Governor.
The Supreme Court, however, said that the result of the vote today will be subject to its verdict on July 11, when it will decide whether a section of MLAs from the Sena should be disqualified, as requested by Mr Thackeray's side.
Mr Thackeray's seeking of court intervention was an attempt to buy time. A total of 39 MLAs from his own party have turned against him, led by Eknath Shinde, a senior Sena leader.
They contend that their faction - far larger in size than the Chief Minister's - is now the real Shiv Sena and that the party must exit the current government, which includes the Congress and Sharad Pawar's NCP as its allies, and re-enter its earlier partnership with the BJP.
Eight days ago, Mr Shinde launched a revolt by exiting Mumbai late at night with a cohort of MLAs. They headed to Surat in Gujarat, clearly guided by the BJP. A day later, they flew to Guwahati after Mr Thackeray's representatives managed to meet with some of them.
In Guwahati, their number grew in high velocity, eventually totalling 39, enough to split the party and ensure Mr Thackeray's removal, not just as Chief Minister, but as President of the party his father founded.
Combined with the BJP and the support of a few independent MLAs, Mr Shinde's side will outnumber the ruling government in a vote. Mr Shinde's side alleges that the Sena's alliance with non-BJP parties is at cross-purposes with its right-wing ideology and the BJP is the natural fit.
They also accused Mr Thackeray of not being available - a charge countered by Team Thackeray saying that while the Chief Minister had not been well and yet maintained a hectic work schedule.
Mr Thackeray, two days after the revolt began, moved out of the Chief Minister's home to make good on a promise he made in a Facebook live to the rebels - that he was wedded to his party and not to power. Though he was reportedly ready to resign as Chief Minister, he was persuaded by Sharad Pawar to fight to the finish.