Referring to his recent statement that the DMK may tie up with the Congress, he said the Thursday decision at the UN Human Rights Council in Geneva had shut "the Tamil doors for the Congress permanently".
By abstaining from voting on a resolution seeking an international probe into allegations of war crimes in Sri Lanka, India should hang its head in shame, Karunanidhi said in a hard hitting statement.
He said the US, which was not affected by the war in Sri Lanka, sponsored a resolution thrice against Sri Lanka for violating human rights. And 22 other countries with no Tamilian roots voted for it Thursday.
India's decision to abstain "is akin to a mother killing her own child", said Karunanidhi, a former Tamil Nadu chief minister who for long was a strong champion of the Tamil separatist campaign in Sri Lanka.
The US-sponsored resolution calls for an international investigation over alleged human rights abuses during the war in Sri Lanka.
Colombo has said it will not agree to an international probe.
India said Thursday it was opposed to an intrusive approach by the UN that undermined national sovereignty.
The resolution was passed by majority vote in the 47-member council, with 23 countries voting for it, 12 opposing and another 12 abstaining.
Karunanidhi denounced the Indian government's logic and said that even Congress members in Tamil Nadu would not accept the argument.
If India believed in non-interference in others' affairs, how did it take sides over South Africa's apartheid policy or help create Bangladesh, he asked.