India's Supreme Court on Wednesday upheld the Mumbai terror attack convict and Pakistani terrorist Ajmal Kasab's death penalty and rejected his appeal against the death sentence in the 26/11 Mumbai terror attacks.

The High Court, in February last year, had upheld the trial court's death penalty for Kasab, the lone surviving gunman who was part of the 10-member team that attacked Mumbai on Nov. 26, 2008, leaving 166 people dead and many more injured. The Mumbai trial court awarded death penalty to Kasab on May 6, 2010.

The 25-year-old Pakistani militant was convicted of criminal conspiracy, waging war against the nation, under Section 302 of IPC (murder) and terror-related provisions of Unlawful Activities (Prevention) Act.

Upholding the death sentence, the Supreme Court bench of Justice Aftab Alam and Justice C.K. Prasad agreed to the trial court's verdict that the case against Kasab fell in the rarest of rare category, Indian media reports said.

"Waging war against the country is the primary and foremost offence committed by Kasab," the bench said. "We are constrained and left with no option but to uphold the death sentence of Kasab."

Kasab had appealed against his conviction and death penalty arguing that he was denied a fair trial since he was not provided legal assistance as mandated under the terms of Article 22 (1) of the Indian constitution and that he deserves leniency as he was "not part of the larger conspiracy." The court-appointed senior advocate Raju Ramachandran argued the case on behalf of Kasab.

Kasab, lodged at the Arthur Road Prison in Mumbai in a high-security cell, had appealed for a reversal of the High Court's verdict through the jail authorities.

Other terrorists in the group of attackers were killed in the police encounter.