South Korea's ousted former President Yoon Suk Yeol, who is facing charges of orchestrating a rebellion when he declared martial law on Dec. 3, arrives to attend his trial at the Seoul Central District Court in Seoul, South Korea, Monday, May 12, 2025. Photo:AP/Ahn Young-joon

Independent counsel Cho Eun-suk asked the Seoul Central District Court to impose the sentence, arguing that Yoon’s actions amounted to "anti-state activities" and describing the decree as a "self-coup."

Yoon, a conservative who was removed from office last spring, remains in custody while facing multiple criminal proceedings tied to the martial law episode and other controversies from his presidency. Prosecutors say the rebellion charge carries the most severe potential punishment.

Cho’s team argued in court that Yoon sought to prolong his hold on power by undermining South Korea’s constitutional system of governance.

Yoon has rejected the accusations, telling the court that the investigations into his conduct have been "frenzied" and marked by "manipulation" and "distortion."

He has maintained that the declaration of martial law was intended to alert the public to what he viewed as the growing threat posed by the opposition Democratic Party, which used its legislative majority to block his political agenda.

Yoon argued that the exercise of presidential emergency powers cannot be treated as rebellion under the law.

The court is expected to deliver a verdict next month. Legal experts have said a life sentence is more likely than execution, noting that South Korea has not carried out a death penalty since 1997.

Yoon is the first South Korean president who has faced a potential death penalty after leaving office since Chun Doo-hwan was sentenced to death in 1996 for various crimes. Chun’s death sentence was later commuted to life in prison, and he was subsequently pardoned and freed.