MK Stalin is Mr Karunanidhi's younger son
MK Karunanidhi, 92, is running for his 12th term as president of the DMK. In party elections scheduled for Friday, Mr Karunanidhi's younger son, MK Stalin, will also seek re-election as Treasurer, which makes him No 3 in the party's hierarchy.
Mr Stalin, 61, denied reports that he wanted to run for the higher office of General Secretary. "Isn't being DMK Treasurer a big position?" he said to journalists.
A few years ago, Mr Stalin was publicly declared by Mr Karunanidhi as his political heir, grafting a huge family rift. Mr Stalin's older brother, MK Alagiri, was expelled from the party in March last year for indiscipline. His dismissal from the DMK for indiscipline came after a long campaign focused on undermining the authority of his younger brother.
Despite threats, Mr Alagiri has not launched his own party, fuelling talk of his interest in reconciliation with his father.
The feud within the first family of the DMK climaxed as the party's political fortunes were crashing. In 2011, it lost the state election to rival J Jayalalithaa. In 2013, Mr Karunanidhi pulled the party out of the coalition government headed by Dr Manmohan Singh, alleging that India was not being severe enough with the Sri Lankan government about its alleged atrocities against the island's ethnic Tamils.
In the national election in May last year, the DMK did not win a single parliamentary seat.