People walk by the Constitutional Court in Seoul, Jan. 2. Yonhap

The Constitutional Court began the second preparatory hearing Friday for President Yoon Suk Yeol's impeachment trial, following his short-lived imposition of martial law last month.

Justices Cheong Hyung-sik and Lee Mi-son presided over the hearing and will decide whether to hold additional preparatory hearings before the formal trial on Yoon's impeachment by the National Assembly, sparked by his martial law bid on Dec. 3.

Ahead of the hearing, legal representatives from the National Assembly claimed an insurrection led by Yoon was ongoing, while Yoon's defense team rejected the notion of an insurrection.

"The insurrection is still not over and is ongoing," Rep. Jung Chung-rae told reporters outside the court. "The whole public is watching through live TV as insurrection leader Yoon Suk Yeol obstructs justice and doesn't respond to a court-issued warrant."

Investigators tried to detain Yoon earlier in the day but decided to suspend their attempt after an hourslong standoff with security personnel at his residence.

Meanwhile, Yoon's legal team called for "thoroughly" reviewing evidence to check for wrongdoing.

"Evidence must be thoroughly contested to see if there was actual wrongdoing," Bae Jin-han, one of Yoon's lawyers, said. "It is not advisable to use the term insurrection."

Yoon has denied charges he incited an insurrection by declaring martial law, arguing it was an "act of governance" and a warning against what he described as an abuse of legislative power by the main opposition Democratic Party.

He currently faces arrest after a court issued a warrant to detain him.

The Constitutional Court has 180 days to decide whether to uphold or dismiss the impeachment from the day it received the case on Dec. 14.

If the impeachment is upheld, Yoon will be removed from office, triggering a snap presidential election within 60 days. If it is dismissed, he will be reinstated. (Yonhap)