The Congress on Tuesday urged Tamil Nadu Governor C Vidyasagar Rao to call a special session of the assembly to test the strength of rival AIADMK factions.
The Congress appeal came after the Supreme Court restored the conviction of party General Secretary V K Sasikala and two of her relatives for corruption.
"The governor must call a special assembly session to find a way forward," Congress leader Randeep Surjewala told reporters.
The Bharatiya Janata Party (BJP) hailed the apex court decision.
BJP leader Nalin Kohli said: "The Governor was clear from the start that there is an uncertain situation which requires to be carefully assessed. Now whatever be the outcome in the AIADMK, it is their internal matter."
The Supreme Court on Tuesday restored the judgment of the trial court convicting and sentencing Sasikala and her two relatives – V N Sudhakaran and Elavarasi.
Justice Pinaki Chandra Ghose and Justice Amitava Roy set aside a Karnataka High Court order acquitting the three and the late Tamil Nadu Chief Minister J Jayalalithaa.
The AIADMK is witnessing a power tussle between the two factions led by Sasiskala and acting Chief Minister O Panneerselvam.