The Dravida Munnetra Kazhagam (DMK), an important constituent of the ruling coalition, has threatened to pull out if the Centre does not ensure that the draft of the resolution is modified to put the Mahinda Rajapaksa regime on the spot.
"India should take steps to amend the American resolution to include that war criminals responsible for the genocide in Sri Lanka be identified, hold a free international enquiry against them and take time-bound appropriate action," DMK chief M Karunanidhi stressed on Friday.
He said that if the UPA does not heed "this request", his party feels "it would be meaningless" for them "to continue in the central government".
Last year, India backed a similar resolution at the UNHRC meeting even though Colombo cried foul over Delhi's change of stance. As some countries which are on Sri Lanka's side are certain to move amendments to the resolution, the Centre is yet to reveal how it will vote this time at the meeting in Geneva.
The UPA is hoping that the resolution will be adopted by consensus. It would placate the human rights activists who have been calling for stronger action against the Lankan government and also allow the DMK to remain in the coalition.
The international community has been urging the Mahinda Rajapaksa regime to rehabilitate the ethnic Tamils ever since the civil war ended in Sri Lanka. Lakhs of civilians were forced to flee when the Lankan military fought pitched battles with the Liberation Tigers of Tamil Eelam (LTTE).
Many of these civilians ended up in refugee camps across Tamil Nadu. Delhi believes that Colombo should be taking care of these persons. Another point of contention is the refusal of Mahinda Rajapaksa to hold talks with the Tamil National Alliance.
India believes that devolution of power to the ethnic Tamils could heal the wounds inflicted during the decades-long conflict in the island nation. However, the Lankan government is apparently not willing to contemplate even a limited devolution.