A former military commander who has accused President Yoon Suk Yeol of ordering the removal of lawmakers from the National Assembly building during December's brief imposition of martial law is set to testify at Yoon's impeachment trial Thursday.

A top South Korean military commander said on Tuesday he trusted President Yoon Suk Yeol to be making a legitimate decision when he declared martial law, but declined to say if the impeached leader gave orders to "drag" lawmakers out of parliament.

The charges are unprecedented for a South Korean president, and if convicted, Yoon Suk Yeol could face years in prison for his shock martial-law decree, which sought to ban political and parliamentary activity and control the media.

Yoon, a former prosecutor, plunged democratic South Korea into political turmoil when he declared martial law on December 3, suspending civilian rule and sending soldiers to parliament

South Korean prosecutors on Sunday indicted impeached President Yoon Suk Yeol on rebellion in connection with his short-lived imposition of martial law.

Yoon attends hearing of impeachment trial The Constitutional Court's eight justices -- (from L to R, rear) Chung Kye-sun, Kim Bok-hyeong, Jung Jung-mi,Lee Mi-son, Moon Hyung-bae, Kim Hyung-du, Cheong Hyung-sik and Cho Han-chang -- sit in their courtroom in Seoul on Feb.

Impeached President Yoon Suk Yeol asked a court Tuesday to cancel his arrest over his brief imposition of martial law. Yoon's legal defense team submitted the request to the Seoul Central District Court as it prepares to hold the first preparatory hearing of his criminal trial on Feb.