India's ruling Congress-led United Progressive Alliance (UPA)'s key southern ally DMK Tuesday pulled out of the coalition over the government's failure to condemn alleged atrocities against ethnic Tamils in neighboring Sri Lanka.

DMK chief M Karunanidhi announced the party's decision to withdraw the support of its 18 members of parliament to the UPA government, saying that it was unhappy on India's stand over Sri Lanka at the United Nations' Human Rights Council.

"The government of India did not even consider the amendments ( to the U.S. resolution in the United Nations) proposed by the DMK. So continuing in this government will be an injustice to the Sri Lankan Tamils," he told the media at party headquarters in the southern state of Tamil Nadu's capital Chennai.

The party's five ministers, including Cabinet-rank minister and Karunanidhi's son, M.K. Alagiri, would tender their resignations during the course of the day, the DMK chief said, adding that his party would reconsider its decision if "the UPA government pays heed to its demands."

The DMK has demanded that the Indian government pass a resolution in parliament condemning the alleged atrocities committed by Sri Lankan forces against Tamils during the island nation's long civil war which ended with the death of Tamil Tigers ' chief V. Prabhakaran.

The southern party has also urged the government to push for stronger language in the UN resolution, including the use of the word "genocide."

Immediately after the announcement by the DMK chief, the Indian government insisted that "it still has a majority" in parliament. "The government is absolutely stable, it will stay in power," Finance Minister P. Chimdambaram said.

The UPA -- which needs 271 MPs to stay in government -- still has the support of 280 MPs, after the withdrawal of support by the DMK. The general elections are due next year.