A flag of the Constitutional Court flutters in the wind in Seoul, Monday. Yonhap

The impeachment trial for President Yoon Suk Yeol over his martial law declaration has only one hearing left, Tuesday, before the court makes a decision on whether to remove him from power.

For the last 10 hearings since Jan. 14, representatives from the National Assembly, who serve as the prosecution in the impeachment trial, debated with Yoon's lawyers over various issues, including whether the declaration of martial law and its accompanying proclamation met the necessary conditions and procedures. It also reviewed if Yoon ordered martial law troops to detain politicians and prevent them from passing a resolution to lift the martial law decree and whether the deployment of soldiers to the National Election Commission (NEC) constituted a violation of the Constitution and other laws.

Yoon attended seven out of 10 hearings to defend himself in court. The court also called in 16 witnesses who were key figures in the martial law fiasco, including former Defense Minister Kim Yong-hyun, Prime Minister Han Duck-soo, former National Intelligence Service (NIS) Deputy Director Hong Jang-won and Lt. Gen. Kwak Jong-keun.

In the final hearing, the president's and the Assembly's sides are expected to present their closing arguments over the issues of contention, with Yoon expected to give final statements himself. Yoon is likely to reiterate his claim that declaring martial law was within his authority and thus did not violate the Constitution, while the Assembly's impeachment panel is expected to assert that it was illegal and unjustified.

Based on the arguments, the court is likely to make a verdict in the middle of March.

Police officers guard the main entrance of the Constitutional Court in Jongno District, central Seoul, Monday. Yonhap

National emergency?

Article 77 of the Constitution grants the president the authority to declare martial law during times of war, serious disasters (whether natural or human-induced, including external threats) or in similar states of emergency, in order to address military necessities or maintain public order.

When making his martial law announcement on Dec. 3, Yoon said it was aimed at eradicating "anti-state forces," a term which he used to describe the opposition-dominant Assembly.

Yoon and his legal team contended that declaring martial law was necessary due to the opposition's attempts to undermine his government through impeachment efforts and budget cuts. They also asserted that troops were dispatched to the NEC headquarters and two other NEC-related facilities in Seoul and Suwon, Gyeonggi Province, to investigate allegations of election fraud.

On the other hand, the Assembly's panel refuted claims that the country was facing a national emergency, stating that there was no justification for deploying military forces to the Assembly. They also criticized Yoon for attempting to confiscate the election commission's computer servers without a warrant based on personal suspicions of election fraud.

Legitimacy of Cabinet meeting

Another contentious issue centers on whether the proper procedures and rules were followed before and after the declaration of martial law.

According to the law, the president's declaration must undergo a Cabinet review. Additionally, when martial law is declared, the Assembly must be notified of the decision.

The Assembly's panel argued that the Cabinet meeting held just before the declaration of martial law lasted only about five minutes and that no minutes were recorded during the meeting. They also claimed that the procedures for notifying the Assembly and the relevant ministries were not followed.

Han testified the Cabinet meeting had "numerous procedural and substantive flaws" and was different from usual Cabinet meetings.

In contrast, Yoon's legal team emphasized the procedural legitimacy of the Cabinet meeting, asserting that the drafting of minutes was a secondary issue.

President Yoon Suk Yeol attends a hearing of his impeachment trial at the Constitutional Court, Feb. 20. Joint Press Corps

Arrest squad allegations

The Assembly's committee raised allegations regarding the deployment of a so-called "arrest squad," which Yoon vehemently denies.

Hong, the former NIS official, testified that Yoon ordered him to arrest key political figures on the night of the martial law declaration. His handwritten note taken during a phone call with Yoon was considered key evidence suggesting that Yoon had issued an unlawful order to arrest politicians.

However, the president's legal team questioned the credibility of his testimony, adding that Hong had different versions of the note.

The Assembly panel also accused Yoon of blocking lawmakers from passing a resolution to lift martial law. The martial law decree prohibited all political activities, including the operations of the National Assembly, political parties, political associations, gatherings and protests. This contradicts Yoon's claim that the martial law imposition was intended to last no more than half a day, merely sending a "warning signal" to the opposition.

Former Defense Minister Kim said he drew up the martial law decree and the president endorsed it.

Once the final hearing ends, the court is expected to issue its ruling within approximately two weeks, based on precedents from past impeachment cases. In former President Roh Moo-hyun's trial, the court ruled 14 days after the final arguments, while in former President Park Geun-hye's case, the decision came 11 days later.

If the court upholds the impeachment, an election must be held within 60 days to choose a new president.