Deepa Jayakumar, 41, who resembles Jayalalithaa but is tubbier than the departed leader when she was in her forties, is the niece of Amma. Deepa's late father Jayakumar was the brother of Jayalalithaa.
Deepa's entry is seen as a direct challenge to Sasikala, Jayalalithaa's aide who took over as AIADMK general secretary on December 31. If Sasikala is now known as Chinnamma (little mother) in a reminder of the Amma legacy, some party supporters are already addressing the niece as "Deepamma".
Hundreds of AIADMK cadres had been converging in front of Deepa's house in T. Nagar in central Chennai almost every day since Sasikala took over as general secretary.
On Tuesday, when Deepa was addressing a crowded media conference, thousands of AIADMK cadres had thronged the road outside her house, forcing police to divert traffic. When Deepa went to pay tribute at MGR's memorial on the Marina Beach today, more than 3,000 cadres waited to welcome her.
Although Deepa, a former journalist with an English daily, denied that the BJP was backing her, the Sasikala group strongly feels that Jayalalithaa's niece would not have taken the plunge without the covert support of some powerful elements.
Deepa said she would reveal her political plan on February 24, which happens to be Jayalalithaa's birth anniversary.
"I need to take the views of the cadres and the general public before announcing my decision which would come on the landmark day," Deepa said.
By giving herself a month, Deepa wants to explore if leaders unhappy with Sasikala's leadership and her family's grip on the party would rally behind her. In the interlude, if the Supreme Court verdict in the wealth case goes against Sasikala, Deepa's acceptance could become more widespread.
Across the state, cadres have floated the "J. Deepa Peravai" (Deepa Forum) and have been urging her to lead the true cadres of Amma in what is seen as a revolt against the takeover of the AIADMK by Sasikala and her relatives.
Many of them collected their AIADMK membership cards to be surrendered at the party headquarters to protest Sasikala's leadership. "While over a crore cadres of the AIADMK are behind Deepa, the present government and party have been captured by just 500 people - MLAs, MPs and party functionaries. This is an artificial government without popular support," claimed K. Bharathi, an AIADMK member from nearby Thrivallur district.
Sensing the mood, Deepa, who initially said she would decide if she would join the AIADMK or start a political party, suggested that she would challenge Sasikala.
"I cannot accept anyone else as leader other than MGR or Jayalalithaa," Deepa said in reply to a question if she would accept Sasikala's leadership.
"My views are not important but I agree with the popular view," she added, hinting that that the public has not relished the way Sasikala grabbed the AIADMK leadership shortly after Jayalalithaa's death.
Deepa contested the claim of Sasikala's husband Natarajan that it was his family that had protected Jayalalithaa and the AIADMK after MGR's death. "What the Sasikala family is claiming is false...."
Speaking in English and Tamil, Deepa appeared a more confident communicator than Sasikala who had merely read out from a prepared Tamil text. Deepa fielded questions, though she did stumble for a reply a few times.
Clad in a red sari, Deepa also wore her hair in a Jayalalithaa-like tuft, something Sasikala too had imitated.
Deepa's entry could spell more trouble for Sasikala whose moves to become chief minister have been checked for now by the Centre. Her husband Natarajan had accused New Delhi of trying to "split the AIADMK and bring down the state government". He had also grudgingly stated that there was no need to change the chief minister now as O. Panneerselvam was providing an effective administration.