SEOUL, South Korea (AP) – In the latest twist in South Korea’s ongoing political crisis, the country’s Constitutional Court reinstated Prime Minister Han Duck-soo as acting leader, overturning his impeachment by opposition lawmakers three months ago.

The court’s ruling on Monday marks just one front in the deepening turmoil as it simultaneously weighs the far more consequential case of conservative President Yoon Suk Yeol, whose December impeachment over his brief but stunning martial law decree has left the country’s leadership in limbo for months.

Here is a look at the court’s decision and what lies ahead.

How Did Mr. Han Get Reinstated?

The prime minister typically holds limited authority as the country’s second-highest official. But Mr. Han, a career bureaucrat who has held various government roles since the 1970s, was elevated as the government’s caretaker after South Korea’s opposition-controlled National Assembly impeached Mr. Yoon on December 14.

Mr. Yoon’s impeachment, triggered by his short-lived imposition of martial law that month, immediately suspended his presidential powers and put his political fate in the hands of the Constitutional Court, which is nearing a decision on whether to formally remove him from office or reinstate him.

As acting president, Mr. Han quickly clashed with the liberal opposition Democratic Party, mainly over his refusal to comply with their demand to immediately fill three vacant seats on the Constitutional Court’s nine-member bench.

The composition of the court is a sensitive issue since removing Mr. Yoon from office requires the support of at least six justices, and a full bench would likely increase the chances of his ouster. Mr. Han said he would not appoint the justices without bipartisan consent, but the Democrats accused him of siding with the conservatives in the governing People Power Party, which has been campaigning for Mr. Yoon’s return to power.

Days after lawmakers impeached Mr. Han on December 27, Deputy Prime Minister Choi Sang-mok, who stepped in as acting president, filled two of the court’s vacancies but refused to appoint a progressive justice nominated by the opposition.

Seven of the court’s eight justices overturned or dismissed Mr. Han’s impeachment, ruling that the accusations against him were either not illegal, not serious enough to warrant his removal or that the impeachment motion had failed to meet the required quorum when it passed through the National Assembly. One justice upheld Mr. Han’s impeachment.

After his reinstatement, Mr. Han called for national unity and emphasized the need to focus on addressing external challenges stemming from U.S. President Donald Trump’s aggressive trade policies.

Does the Decision Affect Mr. Yoon’s Case?

Mr. Han’s case is unlikely to serve as a preview of how the court will rule on Mr. Yoon. Mr. Han played no meaningful role in planning or enforcing Mr. Yoon’s martial law, which was lifted by a legislative vote just hours after Mr. Yoon declared it on the night of December 3.

But Mr. Han’s reinstatement still struck a nerve with the Democrats, who have recently criticized the court for its prolonged deliberation on Mr. Yoon’s case, which has fueled concerns about a divide among justices, potentially paving the way for Mr. Yoon’s return.

Democratic Party leader Lee Jae-myung, who narrowly lost the 2022 presidential election to Mr. Yoon, questioned why the court did not consider Mr. Han’s refusal to appoint the justices an impeachable offense. He said Mr. Han’s actions amounted to a “clear and deliberate violation of his constitutional duty to form a government body.”

Mr. Lee also called for the court to make a swift decision on Mr. Yoon.

Mr. Yoon’s office issued a statement welcoming Mr. Han’s reinstatement, asserting that the court’s decision proved the opposition’s “excessive impeachment attempts were reckless, malicious, and politically motivated.”

How Crucial is Mr. Han’s Testimony?

Mr. Yoon, who is also facing a separate criminal trial on rebellion charges, stands accused of abusing military power, bypassing constitutional and legal protocols to impose martial law, and orchestrating a failed attempt to dissolve the legislature. But the Constitutional Court likely will not take a deep dive into Yoon’s criminal allegations, as it is only required to rule whether or not he can remain in office.

Some experts say Mr. Han’s testimony before lawmakers, investigators and the court regarding the short-lived martial law decree could possibly influence how justices rule on Mr. Yoon’s case.

Among the various accusations against Mr. Yoon, the National Assembly has alleged that he bypassed a constitutional requirement to deliberate in a formal Cabinet meeting before declaring martial law. Mr. Han’s testimony has seemingly supported these claims.

While Mr. Yoon called 11 Cabinet members to his office shortly before declaring martial law on late-night television, Mr. Han has said the gathering did not qualify as a formal Cabinet meeting and that Mr. Yoon unilaterally informed them of his decision rather than inviting deliberation.

Mr. Han and other top officials, including Choi and Foreign Minister Cho Tae-yul, have said they attempted to talk Mr. Yoon out of martial law, citing potential damage to the country’s international reputation and economy. Under South Korea’s constitution, such powers can only be exercised during wartime or comparable national emergencies.