In a statement, the former Tamil Nadu chief minister said the three convicts - Perarivalan, Santhan and Murugan - had been languishing in prison for more than 20 years after being awarded capital punishment.
"Despite pleas by many to the Tamil Nadu government to pass a Cabinet resolution to recommend to the Governor to commute their sentences, no steps have been taken. At least the Centre should do so. I urge the Prime Minister and UPA chairperson to do the needful," he said.
On September 9, the Madras High Court had stayed the execution of the accused for eight weeks. Karunanidhi has been demanding that the three should be set free as they have undergone imprisonment for more than 20 years.