The Constitutional Court has begun procedures for the impeachment trial of Prime Minister Han Duck-soo, a day before argument of merits in the impeachment trial of President Yoon Suk Yeol.

The court on Monday held the first preparatory hearing in Han's trial that lasted for about an hour.

During the hearing presided over by justices Kim Hyung-du and Kim Bok-hyeong, Han's defense team objected to the court's request for records from an ongoing investigation into the martial law incident, citing Clause 32 from the Constitutional Court Act.

The clause stipulates that the court can not request a transfer of records from a case under an ongoing trial or criminal investigation.

Justice Kim Hyung-du, in response, requested teams representing Han and the National Assembly to consult on other means of verifying the case in the absence of investigation records, to avoid having to go through questioning of witnesses.

The team also asked the court to proceed with Han's case first, instead of giving priority to the president's impeachment trial.