The impeachment trial of South Korea's suspended President Yoon Suk Yeol is set to begin on Tuesday, as the Constitutional Court deliberates whether to formally remove him from office over an attempted martial law declaration.

Yoon's controversial power grab on December 3 sparked South Korea's most severe political crisis in decades. He ordered military forces to storm parliament in a failed attempt to prevent lawmakers from overturning his suspension of civilian rule.

Following the incident, Yoon was impeached and suspended from office. Since then, he has remained in the presidential residence, refusing to comply with investigators probing him on charges of insurrection, while relying on his presidential security detail to avoid arrest.

Compounding the crisis, lawmakers last month also impeached Yoon's acting replacement Han Duck-soo, further destabilizing the country. The current interim president has refrained from taking decisive action, instead urging all parties to negotiate a resolution to the ongoing political impasse.

Insurrection?

The first of five scheduled hearings in the trial will commence at 2:00 pm local time (0500 GMT), with subsequent sessions slated for January 16, 21, 23, and February 4. The court is tasked with determining two key questions: whether Yoon’s martial law declaration was constitutional and, if deemed illegal, whether it constituted insurrection.

"This impeachment case focuses solely on the martial law situation, so the facts are not particularly complex," lawyer Kim Nam-ju told AFP.

"Since most of the individuals involved have already been indicted and the facts have been somewhat established, it doesn't seem like it will take a long time."

Despite this, the court has up to 180 days from December 14, when the case was filed, to issue a ruling on whether Yoon violated the Constitution and the Martial Law Act.

Yoon's legal team has stated he will not attend the first hearing, citing safety concerns, but expressed a willingness for him to appear at a later date if security arrangements are resolved.

"Concerns about safety and potential incidents have arisen. Therefore, the President will not be able to attend the trial on January 14," his lawyer Yoon Kab-keun said in a statement sent to AFP on Sunday.

The trial will proceed in Yoon's absence if he does not appear. Notably, former South Korean presidents Roh Moo-hyun and Park Geun-hye also abstained from attending their respective impeachment trials in 2004 and 2016-2017.

Yoon's legal team has urged the court to utilize the full 180-day timeframe to thoroughly examine the circumstances leading to the martial law declaration.

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