The Congress and the Dravida Munnetra Kazhagam (DMK) on Monday failed to reach a breakthrough on Monday over the latter's stance against Sri Lanka, media reports said.
The DMK held on to its call for the Indian government to amend a U.S. sponsored resolution to incorporate the demand for international probe and time-bound action against those who may be found guilty of war crimes in Sri Lanka.
"I have been assured that our demands will be met," Karunanidhi said following his meeting with Union Ministers P Chidambaram, AK Antony and Ghulam Nabi Azad.
Speaking to reporters after the meeting, Azad said, "We discussed the contents of the letter Karunanidhi had written to PM and some amendments. We will convey his suggestions to the Prime Minister."
Karunanidhi on Sunday threatened to snap ties with the Congress-led United Progressive Alliance (UPA) if the Centre did not heed to DMK´s demands against Sri Lanka.
"If our demands are not met, it is doubtful whether our ties with the alliance (UPA) will continue...It won´t continue is sure," Karunanidhi told reporters.
The statement came after he sent a letter to Prime Minister Manmohan Singh and UPA chairperson Sonia Gandhi, saying he felt "let down" by the government on the issue.
Karunanidhi´s threat was graver than his warning two days ago to pull out his ministers from the union cabinet if the government failed to meet his party´s demands.
It came in spite of Finance Minister P Chidambaram hinting at a possible vote against Sri Lanka on Saturday.
"I am confident that if phrases in the UN resolution sought credible independent international probe, India would support it," Chidambaram had said.
The government, which has not taken a clear stance over the Lankan Tamils issue, on Saturday attempted to placate the DMK with Union Minister V Narayanasamy saying the Prime Minister would "definitely consider all aspects" before taking a decision on the resolution.
On Sunday, External Affairs Minister Salman Khurshid said a decision by the government on voting on the UN resolution on Sri Lanka will be taken after consulting all UPA partners.
"They (DMK) are our allies, and whatever decision we take will be done after discussions with them," said Khurshid to a query by reporters in Lucknow.
However, when pressed further on the issue, he said: "We don´t need to reveal everything beforehand."
In the sternest of warnings yet, the biggest ally of the Congress at the Centre demanded that the Indian government bring in certain amendments in a U.S.-sponsored resolution against Colombo at the upcoming session of the UN Human Rights Council later this month.
"DMK will find it meaningless to continue in the Prime Minister Manmohan Singh-led Cabinet if our demand is not obliged to," Karunanidhi said in a statement on Friday.
The DMK, which has 18 members in the parliament, is critical to the Congress to sustain the ruling coalition, which has already seen the pullout of West Bengal Chief Minister Mamata Banerjee-led Trinamool Congress (TMC).
Karunanidhi has called for New Delhi to vote against Colombo during the session of the United Nations Human Rights Council (UNHRC) where the US-sponsored motion puts the island nation in the dock over alleged war crimes.
The DMK wants the government to support amendments in the US resolution in a manner that "those responsible for genocide are identified and an independent international probe is launched against the war criminals within a specified time frame."
Prime Minister Manmohan Singh last week said all efforts are being made for an honourable settlement for Tamil people in Sri Lanka.
DMK MPs have staged a number of walkouts from the Parliament over the last few weeks on the issue.
The issue of Sri Lankan war crimes was re-ignited recently after photos of the alleged cold-blooded killing of Liberation Tigers of Tamil Eelam (LTTE) chief Velupillai Prabhakaran´s 12-year-old son came to light.