Party chief M Karunanidhi said it would strengthen the argument placed by many that India was only helping Sri Lankan government and not the Tamils there or Indian fishermen.
"Indian fishermen will be attacked by Sri Lankan navy from the very ships (proposed to be) given by India for guarding the borders," he said.
Reports in a section of the vernacular media had already described this as adding insult to injury, the DMK supremo said, adding "DMK never believed the criticism (against) Indian government that it aided Sri Lanka in 2009," during the final stages of Ealam War IV war that saw large-scale Tamil civilian casualties.
India plans to supply two Offshore Patrol Vessels, to be built by Goa-based defence PSU Goa Shipyard Limited, to Sri Lanka by 2017-18.