The Trinamool Congress' internal power struggle has now moved into a formal proceeding inside the West Bengal Assembly, with the Assembly Secretariat issuing notices to 10 MLAs aligned with the Ritabrata Banerjee-led rebel camp.

The legislators have been given seven days to respond to a petition seeking their disqualification under the anti-defection law.

The move follows a petition filed by senior TMC MLA Sovandeb Chattopadhyay, who has emerged as the Mamata Banerjee-led faction's nominee in the battle over the Leader of Opposition's post. 

The development came a day after Chattopadhyay approached the Supreme Court seeking the disqualification of Ritabrata Banerjee and nine other MLAs.

The Assembly notices, however, are part of the proceedings and do not mean that the legislators have been disqualified.

The 10 MLAs who have received notices are Ritabrata Banerjee, Arup Roy, Firhad Hakim, Sandipan Saha, Akhruzzaman Ansari, Shiuli Saha, Sabina Yasmin, Biplab Mitra, Javed Khan and Rathin Ghosh.

Ansari has confirmed receiving the notice and said the camp would discuss the matter and respond within the stipulated period.

The dispute stems from the deepening organisational and legislative divide within the TMC following its defeat in the West Bengal Assembly elections in May.

The Ritabrata-led faction has challenged the authority of the Mamata Banerjee camp and has claimed the support of a majority of the party's MLAs.

The contest has also affected the Assembly's leadership structure.

The Speaker recognised Ritabrata Banerjee as Leader of Opposition, a decision challenged by Chattopadhyay before the Calcutta High Court.

At the same time, the two factions are locked in a separate battle before the Election Commission over the TMC's name, organisational control and the party's twin-flower-on-grass election symbol.

The poll panel has been considering submissions from both sides as the state heads towards bypolls.

The dispute has also spilled into Parliament, where disqualification proceedings involving MPs aligned with the rebel camp are underway.

For the Mamata Banerjee-led faction, the Assembly petition is part of its argument that the rebel legislators' actions amount to defection and warrant action under the anti-defection law.

The Ritabrata camp, meanwhile, has rejected the move and described the notices as a routine procedural step following the petition.