Maharashtra legislature secretary has issued show-cause notices to 53 out of the total 55 Shiv Sena MLAs in the state - 39 of the faction led by Eknath Shinde and 14 of the Uddhav Thackeray group.
One of the 14 MLAs from the Thackeray side, Santosh Bangar, joined the Shinde camp on the day of the floor test of the latter's government on July 4.
MLAs from both sides confirmed having received the showcase notice.
Both sides have accused each other of defying the party whip during the Speaker's election and the trust vote on July 3 and 4, respectively, seeking disqualification of the legislators from both sides.
The Shinde faction has not included the name of Aaditya Thackeray, son of former chief minister Uddhav Thackeray, in the list of MLAs against whom they have sought disqualification.
The notices have been issued under the Members of Maharashtra Legislative Assembly (disqualification on grounds of defection) rules.
The legislators have been asked to explain their stand within seven days, sources said.
The Shiv Sena has 55 MLAs in the 288-member Assembly, whose current strength is 287 due to the death of a Sena legislator.
In the trust vote, 164 MLAs voted for the motion of confidence, while 99 voted against it.
After winning the trust vote in the state Assembly on July 4, the Eknath Shinde faction of the Shiv Sena issued a notice to 14 legislators from the Uddhav Thackeray camp for violating a whip issued by the Sena whip and Shinde loyalist Bharat Gogawale.
A day before the floor test, Maharashtra Assembly Speaker Rahul Narvekar had recognised Gogawale as the Shiv Sena's chief whip, removing Sunil Prabhu, who belongs to the Thackeray faction.
On July 3, Rahul Narvekar of the BJP was elected Speaker of the Maharashtra Assembly. He had polled 164 votes, and he defeated Uddhav Thackeray-led Shiv Sena candidate Rajan Salvi, who got 107 votes.
