The DMK on Monday decide to not give support to UPA-II from outside in the key party executive meet held in Chennai.
The party withdrew support for the rulling alliance last week over Sri Lankan Tamils issue.
Meanwhile, in further signs of fissures within DMK, party chief M Karunanidhi's son MK Alagiri on Monday skipped the crucial executive committee meet.
Alagiri left for Madurai by a morning flight, sources said.
Former Union minister MK Alagiri met his father and party chief M Karunanidhi and conveyed his strong opposition to the “manner” in which the DMK had withdrawn its ministers from the Centre.
On Saturday, Karunanidhi had told DMK workers the party would be “finished” in elections if it did not stay united, especially in the wake of “recent developments” — seen as a veiled warning to Alagiri.
Alagiri is upset with younger brother MK Stalin, Karunanidhi’s political heir, for reportedly pushing their father to withdraw support.
To show his annoyance at not being consulted on the “timing”, Alagiri had submitted his letter of resignation to the PM separately, refusing to go with the other DMK ministers.
When the CBI raided Stalin’s house a day after the pullout, he had sought to play it down even as his brother cried political vendetta.
Karunanidhi and other senior DMK leaders, meanwhile, are miffed with Alagiri for calling on Congress leaders, including the Prime Minister, Sonia Gandhi, P Chidambaram and GK Vasan.
On Sunday too, Alagiri informed his father about his meeting with Manmohan Singh and Gandhi.
Monday's conclave, DMK sources said, will endorse the party's decision on the Sri Lankan Tamils issue.
It plans to adopt a strongly-worded resolution slamming the Centre and Congress for India's failure to get the UN Human Rights Council to set up an internationally-monitored tribunal to probe the alleged genocide following the 2009 war.
Meanwhile, the Congress unit in Tamil Nadu has its own problems, with sources saying the snapping of ties by the DMK has damaged its base.
Shipping minister GK Vasan is under pressure from the party cadre to revive the Tamil Maanila Congress, which his father GK Moopanar had founded in 1996. It was later merged with the Congress.