Geelani, himself awarded capital punishment in the Parliament case, but subsequently acquitted by the Delhi High Court, told PTI here that Murugan, Santhan and Perarivalan had already suffered imprisonment for the past 20 years.
"Hanging them now is not legal. Which law permits it?" he asked. He said he was against capital punishment to anybody.
Geelani said he had come to Chennai to express solidarity with the agitators who were pressing against hanging of the three, who are set to be executed on September 9.
Geelani claimed the Rajiv Gandhi assassination case was not "properly investigated" and the acccused could not be hanged on the basis of an improper investigation. He would try to go to Vellore prison today to meet the three in jail, Geelani said.