Antony, Mukherjee, Sonia, Singh and Karunanidhi attend UPA meeting in New Delhi
(L-R) India's Congress party leaders A. K. Antony, Pranab Mukherjee, party chief Sonia Gandhi, Prime Minister-elect Manmohan Singh, and M. Karunanidhi chief minister of the southern Indian state of Tamil Nadu attend the United Progressive Alliance (UPA) meeting in New Delhi May 20, 2009. Singh vowed on Tuesday to revive growth and spread the benefits of economic expansion that swept his coalition back to power with a decisive mandate in a general election.REUTERS/B Mathur (INDIA POLITI

The Congress-led United Progressive Alliance (UPA) coalition government is hanging on edge after Dravida Munnetra Kazhagam (DMK), its major ally, on Tuesday withdrew its support to the government over the Sri Lankan Tamils issue.

The DMK's decision has led to the possibility of early polls with the UPA coalition being reduced to minority.

Besides quitting the government, the M Karunanidhi-led party also withdrew outside support over the centre's failure to amend the UN resolution against Sri Lanka for alleged war crimes committed against the Tamilians.

The move from the DMK came a few days before the resolution would be put to vote on Friday.

The DMK and the All India Anna Dravida Munnetra Kazhagam (AIADMK), regional parties in Tamil Nadu have been demanding that the words "Eelam" and "genocide" be introduced in the UN resolution.

"The DMK has always worked for the Tamils and has been demanding a tough stance against the Sri Lankan government over war crimes against Tamils," Karunanidhi said while addressing a press conference in Chennai. He also said that the government is not doing enough for the Tamil cause.

The United Nations Human Rights Council (UNHRC) passed a resolution against Sri Lanka for the alleged war crimes last year after India and 23 other countries voted in favour of the US-sponsored resolution. Through the resolution, the United States, the European Union and India urged Sri Lanka to investigate the atrocities committed both by the Sri Lankan army and the Liberation Tigers of Tamil Eelam (LTTE).

Meanwhile, Finance Minister P Chidambaram said that the government is stable despite DMK's withdrawal of support. He expressed optimism as Karunanidhi said that he would reconsider his decision based on the outcome of the resolution.

"The government is stable, the government will continue to stay in power," Chidambaram told CNN IBN. "Karunanidhi is a senior leader; we have taken note of his statement. We respect his statement. DMK requests are under consideration."

The UPA government is now reduced to minority following the exit of the DMK, which has 18 members in the Lok Sabha (Lower House) and six members in the Rajya Sabha (Upper House).

The Lok Sabha has 539 MPs at present (four vacant seats) and the halfway mark is 270. The UPA, which had 250 seats - Congress 202, DMK 18, NCP nine, RLD five, others 16 - is now reduced to 232 following the exit of DMK. The coalition also has outside support from several parties like SP (22), BSP (21), RJD (3), and JDS (3), taking the total count from these parties to 49.

The current strength of the UPA is 271 including outside support, while that of BJP is 152. The Left and other parties make up for 88.

The figures have given a clear message that further withdrawal of support even by small parties like RJD and JDS, which have three MPs each, would force the government to step down and go for early polls.

The last time the UPA government received a huge blow was when Trinamool Congress (TMC), which has 25 MPs, withdrew its support in September last year over foreign direct investment (FDI) in retail sector, diesel price hike and restriction on the supply of LPG cylinders.