India's Central Government has rejected a proposal by Tamil Nadu for the release of seven people convicted over the assassination of the then prime minister, Rajiv Gandhi.
In a letter that was formally accepted by the Supreme Court on Friday, the Centre said the case "an unparalleled act in the annals of crimes committed in this country".
"The brutal act brought the Indian democratic process to a grinding halt inasmuch as the general elections to the Lok Sabha and Assemblies in some States had to be postponed,” the letter added.
Tamil Nadu had launched the request for the release of those convicted in March 2016.
The Centre failed to respond however for over two years, leading to the Supreme Court ordering it to do so.
Tamil Nadu's request to the Centre followed a decision in 2015 by a Constitution Bench that states could not unilaterally remit a life sentence in cases that were investigated by a central agency under central laws.