Uddhav Thackeray's Shiv Sena faction has approached the Supreme Court against Maharashtra Governor Bhagat Singh Koshyari's decision to invite Eknath Shinde to form government in the state.
Team Thackeray leader Subhash Desai has also challenged Monday's assembly proceedings which saw the new Maharashtra Chief Minister breeze through a test of majority.
The Thackeray faction argues that 16 rebel MLAs against whom disqualification proceedings were pending should not have participated in the vote.
Uddhav Thackeray's team has moved fresh disqualification proceedings against all the rebel MLAs who voted in the assembly to elect a new Speaker's election and in the test of majority. It has also moved a no-confidence motion against new Speaker Rahul Narvekar from team Shinde. Subhash Desai, in his petition, asks the Supreme Court to decide on the disqualification of MLAs.
Eknath Shinde, backed by the BJP, led a coup in the Shiv Sena against party chief Uddhav Thackeray, drawing most MLAs on his side and bringing down his government.
Mr Shinde was sworn in as Maharashtra Chief Minister on June 30, with the BJP's Devendra Fadnavis as his deputy.
Four days later, Mr Shinde sailed through a trust vote with 164 votes in the 288-member assembly, way above the simple majority mark of 144. Only 99 MLAs voted against him.
The tussle for control of the Shiv Sena is playing out on different turfs.
The Supreme Court is already hearing another case involving the disqualification notices served by team Thackeray to 16 MLAs days after Eknath Shinde launched his revolt.
The court will take up both the cases on Monday. A decision may impact Eknath Shinde's government.
Uddhav Thackeray has lost most of his party MLAs to what started out as the rebel faction but is now the bigger group, claiming to be the real Sena.
Many corporators are also switching to Eknath Shinde's faction, weakening Uddhav Thackeray's control over Maharashtra civic bodies, the Shiv Sena's strongest domain.