Umar Patek, accused of playing a key role in the Bali bombings, insisted Thursday the attacks that killed 202 people were "against my conscience" and begged for a light sentence.
In emotionally-charged testimony, Patek, 45, maintained he played only a minor role in the 2002 bombings and had shown remorse by apologising to the victims' families.
Prosecutors have recommended a life sentence for Patek, claiming he was a main bombmaker in attacks on two nightclubs on the Indonesian resort island which killed many tourists.
"I only helped to mix less than 50 kilograms of chemicals," Patek said, reading from a lengthy statement with Koranic verses in Arabic. He added that others mixed a remaining 950 kilograms (210 pounds) for the explosives.
"I did it half-heartedly, only because the person who was mixing looked tired and tense. It's not my soul's calling and it's against my conscience."
"I will turn 46 in 50 days, which is considered old, and a long term behind bars will be too severe. I am yet to have children," he told the West Jakarta District Court.
"I hope the judges will consider my plea and give the lightest possible verdict that is true and fair."
He also urged the panel of five judges not to be influenced by "stigma surrounding my identity, theories, opinions and speculation in the mass media in making a final decision".
He criticised prosecutors for not considering the points raised by witnesses in drafting the recommendation.
"All the facts uncovered in the trial specifically from witnesses and my statements were thrown aside," Patek said, raising his voice.
"Their recommendation was simply made by copying and pasting from the indictment."
Patek, part of the Jemaah Islamiyah terror network, was arrested last year in the Pakistani town of Abbottabad, four months before US commandos killed Al-Qaeda chief Osama bin Laden there.
Indonesian prosecutors stopped short of recommending the maximum death penalty last week, arguing that Patek's remorse should spare him from the firing squad. Three of the Bali bombers have already been executed.
At the trial which started in February, Patek has repeatedly denied any major involvement. He claimed he had a change of heart and tried to stop the attacks at the last minute.
The court is expected to announce its verdict in June.
Patek was once the most-wanted terror suspect in Indonesia and spent nearly a decade on the run with the US offering a $1 million bounty for him under its rewards for justice programme.