Upset at not being consulted about the decision to quit the Congress-led UPA, party chief M Karunanidhi's elder son MK Alagiri boycotted a crucial DMK executive council meeting on Monday.
Claiming he was unwell, Alagiri took a flight to Madurai, further underlining the rift in the party.
On Sunday, Alagiri had spent half-an-hour with Karunandhi to explain his reasons for not pulling out and update him about his meetings with Prime Minister Dr Manmohan Singh and Congress chief Sonia Gandhi, said party sources. Alagiri had submitted his letter of resignation to PM separately, refusing to go with the other DMK ministers.
His absence at Monday's meeting was downplayed by partymen, who said it hardly mattered as the party fully backed the leadership's decision to pull out of the UPA on the Sri Lankan Tamils issue.
In a resolution, the party also formally thanked the UPA for the projects given to Tamil Nadu, hinting that its presence in the government was responsible for the same.