"Former Chief of Staff Kim is linked to all the grounds for impeachment, while former Senior Secretary Woo is linked to the investigation into Lotte," he said.

Lotte is one of several conglomerates suspected of providing funds to Choi under pressure from the presidential office.

The parliamentary impeachment panel serving as the prosecution suggested the lawyers request written statements instead, but Lee insisted questioning the 39 in court would help the justices decide on their ruling.

Chief Justice Park Han-chul said they would decide whether to accept the request at the next hearing scheduled for Wednesday.

Observers have predicted the court's proceedings could wrap up as early as end of February, although no date has been announced. 

Park is immune from prosecution while in office, and a delay in the court's deliberations could protect her from a special prosecutor investigating the scandal under a deadline. 

It could also help her buy time to recover some of her lost public support that can influence the verdict by the Constitutional Court. After almost universal condemnation, there has been growing suspicions by conservatives who are loyal to Park that the investigation carried out by state prosecutors and the media may have been incomplete. (Yonhap)