South Korea's Yoon to attend impeachment trial for the first time on January 21

Seoul: South Korean President Yoon Suk Yeol is due to attend on Tuesday a Constitutional Court hearing of his impeachment trial where the detained leader may get a chance to argue his case or answer questions over his short-lived bid to impose martial law.

Yoon has been incarcerated since last week under a separate criminal investigation into whether he led an insurrection by seeking to impose martial law in early December, which shocked the nation and was overturned within hours by parliament.

His lawyers have said Yoon will appear on Tuesday at the Constitutional Court, which is reviewing an impeachment motion that accused him of violating his constitutional duty. The judges will decide whether to remove him from office permanently or reinstate him.

Seok Dong-hyeon, a lawyer advising Yoon, said the team will do their best to help the president "make necessary statements."

Yoon may be given the opportunity to speak in court and also may be questioned by a Constitutional Court justice, a court spokesperson said on Tuesday.

Yoon's decision to attend the impeachment hearing contrasts with his vigorous resistance to criminal proceedings against him where he has refused to answer summons by investigators or attend interrogation sessions.

Yoon's legal team has denied he masterminded an insurrection, a crime in South Korea punishable by life imprisonment or even technically by the death penalty.

When oral arguments at the impeachment hearing began last week, lawyers for Yoon said the impeachment was a political attack against the president by opposition parties abusing their parliamentary majority and it had nothing to do with safeguarding constitutional order.

The main opposition Democratic Party, joined by minority parties and also 12 members of Yoon's People Power Party, voted with a two-thirds majority to impeach Yoon on Dec. 14.

Security has been heightened at the Constitutional Court in central Seoul, after a mob of angry Yoon supporters went on a rampage through the district court that issued a warrant to extend his detention early on Sunday.

Dozens of police buses were lined bumper-to-bumper on both sides of the street in front of the court to limit access into the premises hours before the 2 p.m. (0500 GMT) scheduled start of the hearing.

Yoon was expected to be driven from the Seoul Detention Centre where he is being held by correctional service vehicles escorted by a Presidential Security Service motorcade.