The DMK party led by M. Karunanidhi pulled out of the Congress-led UPA coalition on Tuesday in protest against the government's position on a US-backed United Nations resolution on war crimes allgedly carried out during the Sri Lanka's civil war, reuters news agency said.
The Dravida Munnetra Kazhagam (DMK) is based in Tamil Nadu, and has often pressured the government to do more to protect Sri Lanka's minority Tamil population.
The DMK has 18 seats in the Lok Sabha as part of Prime Minister Manmohan Singh's coalition, which already rules in a minority. Singh's Congress party can continue to govern with parliamentary support from two other regional parties.
The DMK ministers are set to resign from the UPA government.
Addressing a press conference in Chennai, DMK chief Karunanidhi said that our ministers will submit their resignations shortly.
"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.
Karunanidhi had yesterday said he felt "let down" by the "lukewarm" response of the Centre and had demanded amendments in the resolution on Sri Lanka.