Entrance of the Constitutional Court of Korea in Seoul / Yonhap

The Constitutional Court is grappling with unprecedented challenges as it navigates several critical legal issues tied to multiple impeachment motions, including those against President Yoon Suk Yeol and former acting President and Prime Minister Han Duck-soo.

In addition, the court is tasked with handling an injunction and a competence dispute case filed by the ruling People Power Party regarding the legality of the impeachment motion against Han, specifically questioning the quorum required for the motion.

A key question in Han's case is whether the quorum for impeaching the acting president should follow the constitutional requirement for the president — two-thirds of the full National Assembly (200 seats) — or the lower quorum for Cabinet members, such as the prime minister, which is a majority of the Assembly (151 seats).

With the impeachment motion against Han passing on Friday with 192 votes in favor, the Constitutional Court's ruling on this matter will significantly impact the future of state affairs, including the impeachment trial of Yoon.

This mounting pressure is further intensified by the fact that only six justices remain on the court, with three seats still vacant since October.

On a related note, another significant legal matter is whether the court can deliver rulings on 10 pending impeachment cases, including those against Yoon and Han, with only six justices.

The Constitutional Court is currently deliberating whether it can make decisions with only six justices.

Although a quorum of six is theoretically sufficient for decisions on unconstitutionality and impeachment if all present justices agree, there is internal disagreement about the propriety of making such decisions with a reduced bench. Previously, the consensus was to wait for new appointments.

During the injunction case involving Lee Jin-sook, chairperson of the Korea Communications Commission, the court determined that hearings for impeachment cases could proceed with six justices.

However, it did not make a clear ruling on whether decisions could be issued with this number of justices. It only stated then that "at least six justices' approval is required for an impeachment ruling" and "if the opinions of the six justices are divided, the decision can be postponed until the vacant positions are filled."

The issue is that any decision made with only six justices, whether on impeachment trials, authority disputes, injunctions, or constitutional complaints, could face legitimacy challenges due to the absence of one-third of the justices.

Amid these developments, some main opposition Democratic Party of Korea members suggest pursuing further impeachment if Choi Sang-mok, now acting president, deputy prime minister and finance minister, does not appoint justices. This could lead to successive impeachments of Cabinet members acting as president, creating a cycle of impeachment due to the refusal to appoint justices.

The court's public relations official said earlier this month that its acting Chief Justice Moon Hyung-bae stated that the question of whether a ruling can be made with six justices is still "under discussion."