Attacking Bharatiya Janata Party's (BJP) prime ministerial candidate Narendra Modi, Law Minister Kapil Sibal questioned the Gujarat chief minister's silence.
"Today, I ask why is Narendra Modi quiet on this issue? The sad reality is that some political parties have always remained silent on this issue, which sends out a wrong message," said the Congress leader.
"In some states, fake encounters are taking place in the name of terrorism while in other states, terrorists are being freed. This is wrong," he added.
Information and Broadcasting Minister Manish Tewari too asked parties to rise above petty politics.
"The assassination of Rajiv Gandhi was an attack on the unity and integrity of India. This matter has to be taken seriously. All political parties should rise above petty politics," he said.
Meanwhile, the BJP said that it sympathized with the Congress party on the issue but the party should have decided on the mercy petitions of the accused while it could.
"Why did the government sit on their mercy petition? Why couldn't they take a decision?" asked BJP vice president Mukhtar Abbas Naqvi.
Tamil Nadu Chief Minister J. Jayalalithaa Wednesday announced the release of convicts V. Sriharan alias Murugan, T. Suthendraraja alias Santhan, Robert Payas and Jayakumar (Sri Lankans) and A.G. Perarivalan alias Arivu, Nalini and Ravichandran (Indians), who all were convicted in the Rajiv Gandhi assassination case.
All seven have been in prison since 1991, the year a woman Tamil Tiger suicide bomber blew up former prime minister Rajiv Gandhi at an election rally near Chennai.
The Tamil Nadu government's decision came a day after the Supreme Court commuted the death sentence awarded to Murugan, Perarivalan and Santhan citing the inordinate delay in deciding their mercy petitions.