A five-member DMK delegation headed by TR Baalu handed over the letter by party supremo M Karunanidhi to President Pranab Mukherjee at 10.30 PM on Tuesday at Rashtrapati Bhavan withdrawing support of its 18 Lok Sabha MPs to the UPA government.
The DMK ministers will meet Prime Minister Manmohan Singh on Wednesday to submit their resignations, Baalu told reporters after meeting Mukherjee.
"The letter of withdrawal of support from our party chief Karunanidhi has been handed over to the President just now. Tomorrow, our ministers will hand over their resignations to Prime Minister before 12 noon (On Wednesday)," he said on Tuesday.
Replying to questions about possibility of a reconciliation with Congress over the issue, Baalu said, "I don't think there is any little chance of reconciliation because the government has miserably let us down as far as Sri Lankan Tamils issue is concerned. For more than two years we approached the government."
The withdrawal will end the DMK's nearly nine-year-old presence in the ruling UPA.
Read more: DMK says won't even give outside support to UPA
Baalu, who flew into Delhi Tuesday evening from Chennai carrying the letter of the withdrawal of support from DMK supremo M Karunanidhi, met party MPs before going to Rashtrapati Bhavan to hand over the letter for the president.
Earlier in the day, DMK chief M Karunanidhi announced that his party was leaving both the multi-party coalition and Prime Minister Manmohan Singh's government after New Delhi's failure to take a hard line against Sri Lanka.
10 things to know about the Sri Lankan Tamils issue
The UPA government moved to bring a resolution on the Sri Lankan Tamil issue in Parliament in an attempt to placate the key ally which has set it as one of the conditions for reconsideration of its decision.
Meanwhile, sources said the government is drafting a resolution to be brought in Parliament.
However, the DMK has made it clear that it would reconsider its decision if India supports a strong resolution at the UN Human Rights Council and brings a resolution in Parliament on the issue.
Earlier, finance minister P Chidambaram insisted that the government faces no threat and that consultations have been initiated with political parties on DMK's demand that Parliament should adopt a resolution on human rights violations in Sri Lanka.
Read more: US-sponsored resolution on Lanka has two major changes
Chidambaram said the Congress Core Group, headed by party chief Sonia Gandhi, had considered the two suggestions made by DMK at length.
He sought to mollify Karunanidhi, saying his "statement deserves all respect".
Asked whether he was hopeful that DMK will reconsider its decision, Chidambaram said, "According to the media, the DMK president has said that he will review its decision if a resolution is brought before Parliament. We take note of that statement also."
Read more: DMK withdrawing support: history could turn full circle
He insisted that the government is stable and will continue.
"Let me assure everyone that the stability of the government and the continuation of the government are not an issue. The government is absolutely stable and enjoys majority in the Lok Sabha," he said.
"The government has a majority in the House," Chidambaram said responding to repeated queries on the issue of the government's stability.
His statement came hours after Karunanidhi announced that the DMK will pull out of the government over the Lanka Tamils issue. The DMK has 18 members in the Lok Sabha and the UPA with the support of the DMK has 303 MPs in the 543-member House.
On the issue of a resolution moved at the UNHCR against Sri Lanka which DMK wants India to support, he said that the government is examining the final draft which reached in New Delhi late on Momday night.
Karunanidhi had earlier warned that he would withdraw unless the government supported a resolution at the United Nations Human Rights Council in Geneva that condemned "genocide and war crimes" in Sri Lanka.
Sonia pitches for credible probe
Congress president Sonia Gandhi on Tuesday backed the southern ally's demand for an independent and credible probe into "unspeakable atrocities" on ethnic Tamils in Sri Lanka, saying these cannot go un-investigated.
She said that the Sri Lankan Tamils continue to be denied legitimate political rights and expressed pain and anguish over this state of affairs.
"We are most pained at the manner in which their legitimate political rights continue to be denied to them. We are anguished by reports of unspeakable atrocities on innocent civilians and children, especially during the last days of the conflict in 2009," she said.
Sri Lankan forces ended a decades-long civil war with a 2009 onslaught against Tamil Tiger separatists which has since been dogged by war crimes allegations.
The UN estimated that some 40,000 people were killed in the final months of the war, while rights groups put the death toll even higher. Sri Lanka denies that its forces killed civilians.
How the political circle reacted to the pullout:
DMK chief M Karunanidhi: Since it would be a big harm to Tamil race if DMK continues in central government when a situation has been created which won't benefit Eelam Tamils, DMK has decided to immediately pull out of the union ministry and the UPA.
Congress president Sonia Gandhi: The plight of Tamils in Sri Lanka is close to our hearts… We are anguished by reports of unspeakable atrocities on innocent civilians and children... We demand an independent and credible inquiry into the violation of human rights in Sri Lanka.
Finance minister P Chidambaram: Let me assure everyone that the stability of government and its continuation are not an issue. The government is absolutely stable and enjoys majority in the Lok Sabha.
Read the US resolution at UNHRC on Sri Lanka human rights issue
BJP vice president Mukhtar Abbas Naqvi: The government is on a ventilator...It does not have a majority now. It should go.
Tamil Nadu chief minister J Jayalalithaa: When the war in Sri Lanka was at its peak in 2009, he (Karunanidhi) embarked on a three-hour fast drama. He neither pulled out his party nominees from the government nor withdrew support to it.
Bihar chief minister Nitish Kumar: Congress knows the trick of remaining in power. The situation will change by the evening. DMK is an important partner of UPA. If UPA wishes to continue in power it has to accept the demand of DMK.
Uttar Pradesh chief minister Akhilesh Yadav: SP geared up for a national stage in 2014 polls. We are in fact working on a third front for 2014.
SP leader Ram Gopal Yadav: No one has pulled out. This is only to blackmail the government. It is stable
BSP chief Mayawati: The UPA government is not in a minority. We will support it.
NCP vice president Praful Patel: Let us not jump to any conclusion. DMK has said they would reconsider if parliament passes a resolution on the Lankan Tamils issue.
CPM leader Sitaram Yechury: Right now the situation is in a state of uncertainty. They (DMK) have formally announced pulling out of UPA and the government is in minority because of this.
Shiromani Akali Dal chief Sukhbir Singh Badal: With DMK withdrawing support to UPA and SP breathing down its neck, early polls to Lok Sabha are inevitable.
INLD leader Abhay Singh Chautala: Early Lok Sabha polls are inevitable as Congress is in a desperate situation, especially after DMK has pulled out.
Jaya slams Karuna, calls pullout 'drama'
Slamming DMK president M Karunanidhi, Tamil Nadu chief minister J Jayalalithaa described his party's withdrawal from the UPA over the Sri Lankan Tamils issue as a "drama" and indicated it was an action which came too late in the day.
Read more: Jaya call pullout 'drama'
"When the war in Sri Lanka was at its peak in 2009, he embarked on a 'three-hour fast drama,' but neither pulled out his party nominees from the government nor withdrew support to it," she said in a statement in Chennai.
"People are tired of the countless dramas by Karunanidhi. While the revived TESO had failed to find any support among people and students, he seems to aim at minimising the blame by enacting the latest drama. His aspirations would not come true and people will teach him a right lesson for his drama," she said.