Chennai: M. Karunanidhi's older son M.K. Alagiri has warned of "dire consequences" if he was not readmitted into the DMK, as sibling rivalry between the late party patriarch's sons bubbled to the surface again barely three weeks after the leader's death.

The warning came a day after Karunanidhi's younger son and working president M.K. Stalin filed his nomination for the post of DMK chief, formally kicking off the process to elect him as his father's successor at Tuesday's general council meeting in Chennai.

"There were some who were preventing my re-entry into the party even when Kalaignar (Karunanidhi) was alive, though the patriarch was about to take me back. Besides, as Stalin was made the working president when Kalaignar was alive, I did not object to it. Now that Kalaignar is no more I want to save the party. If I am not readmitted into the party, it will have to face dire consequences," Alagiri told reporters in Madurai on Monday.

Alagiri, expelled from the party by Karunanidhi in 2014, had earlier announced that he would lead a peace rally in Chennai on September 5 in his father's memory.

Alagiri didn't elaborate on his threat but the warning came amid rumours that the estranged son might join hands with superstar Rajinikanth who is likely to float a party anytime soon.

At Tuesday's general council, Stalin is likely to be elected as party chief as his was the only nomination received for the post till Sunday evening. If that happens the difference in the political careers of the two brothers would be complete.

While Alagiri, who was the DMK's south zone secretary, was expelled for criticising party decisions and violating discipline, Stalin has been a former deputy chief minister of Tamil Nadu, apart from becoming youth wing secretary, party treasurer and working president.

Karunanidhi had four sons - M.K. Muthu (born to his first wife Padmavathi) and Alagiri, Stalin and Tamilarasu (born to his second wife Dayalu Ammal). When Karunanidhi tried to project Muthu in the film industry, it resulted in the expulsion of matinee idol M.G. Ramachandran from the party, paving the way for the birth of the AIADMK.

When Muthu fell out of favour, Karunanidhi projected Stalin as his political heir, which eventually led to the expulsion of his close confidant V. Gopalasamy (Vaiko) and the birth of the MDMK.

Stalin, a mild-mannered man, took care to maintain an excellent rapport with the nonagenarian Karunanidhi till his death on August 7. But party leaders say that Alagiri, brutally frank in his opinions, had rarely been polite even to his father.

Even when he was made the southern zone secretary, with his base in Madurai, Alagiri felt that it was to shunt him out of Chennai, the state's political capital.

Although Alagiri was made a Union minister in UPA-II, thanks to Karunanidhi, Alagiri felt ill at ease as his brother was the deputy chief minister.

Sources said Alagiri considered the recent developments in the state - the unseemly squabbles within the ruling AIADMK following chief minister Jayalalithaa's premature death in December 2016 - as a heaven-sent opportunity to strike.

But he also knows that his brother has brought almost all the district party secretaries under his control. His comments, including one earlier when he told reporters that all DMK "loyalists" were with him, have come in this backdrop.

Alagiri, a man of few words didn't say much more on Monday. But he asked the media to wait for the September 5 rally in Chennai.