44-year-old Nalini conveyed her decision to her lawyer P Pugazhendhi, who met her at the high security women's special prison at Vellore on Tuesday evening.
Pugazhendhi, who was the first to meet Nalini after the government's rejection of her plea, said she was shocked to hear about the decision, which was conveyed to the court on Monday through Advocate General P S Raman.
The lawyer claimed that though the Prison Advisory Board (PAB) committee members, who considered her premature release request, had given a report in her favour, the government has gone by a report of the Royapetta Police Station, which had anticipated law and order problem in the area if she was freed.
Though Nalini's mother and brother were staying in the area for over a decade, there was no law and order problem, he said, adding that Nalini felt that it was wrong on the part of the government to "totally rely" on the inspector's report to reject her request.
Nalini was sentenced to death by a special court along with 25 others in January 1998 in the assassination case and the Supreme Court had confirmed the capital punishment for her and three others.
However, her death penalty was commuted to life by the state government on April 24, 2000 allowing a clemency petition. Rajiv's widow and Congress President Sonia Gandhi had favoured reduction of her punishment considering the plight of Nalini's young daughter.
An earlier plea by Nalini for premature release was rejected by authorities in October 2007.
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'Report on Nalini's plea will take more time'