South Korea’s Impeachment Process, Explained

SEOUL, South Korea — South Korean lawmakers will vote on Friday on the impeachment of President Park Geun-hye, who is accused of helping a friend commit extortion. If she is forced from office, it will be a first for South Korea, but the process is long and uncertain. Here’s how it works.

What is Ms. Park accused of?

Prosecutors say Ms. Park conspired with Choi Soon-sil, an old friend, to extort tens of millions of dollars from South Korean businesses. Ms. Park cannot be indicted while in office, but she has been identified as a criminal suspect, which had never happened to a president before.

She has also been accused of helping Ms. Choi illegally gain access to confidential government documents. Opposition parties say the combined allegations are serious enough to warrant her removal from power; some members of her own party agree, as do leading South Korean newspapers and most of the public, according to polls. Huge protests have been held in Seoul demanding that Ms. Park step down, but she has refused.

What is required for impeachment?

The 300-member National Assembly is expected to vote on an impeachment bill on Friday, the last day of the current legislative session. If 200 members vote yes, the National Assembly will formally ask the Constitutional Court to impeach her and remove her from office. To reach 200 votes, the opposition lawmakers will need at least 28 members of Ms. Park’s conservative party, Saenuri, to join them.

An impeachment motion must accuse an official of violating “the Constitution and the laws,” but the National Assembly is not required to prove those charges.

What happens next?

If the impeachment motion passes, Ms. Park will be suspended from office, and the country’s No. 2 official, Prime Minister Hwang Kyo-ahn, will become acting president. The Constitutional Court will then have 180 days to rule on whether to impeach Ms. Park.

The court must decide whether she is guilty of the crimes that the National Assembly claims she committed and whether they are serious enough to merit impeachment.

If at least six members of the nine-judge court vote to impeach, Ms. Park will be impeached and removed from office. South Korea will have 60 days to elect a successor, with Mr. Hwang carrying out her duties in the meantime.

If fewer than six judges vote for impeachment, Ms. Park will immediately be returned to office.

Six of the current judges were appointed by Ms. Park or her conservative predecessor, or are otherwise seen as being close to her party. But plenty of conservatives think Ms. Park should go.

There could be another complication: Two of the judges are set to retire by March. If the court has not ruled by then, some legal scholars say, those judges could not be replaced, because the president formally appoints them and Ms. Park would still be suspended. That would improve Ms. Park’s odds, because six of the remaining seven judges would have to vote to impeach her.

Has a South Korean president ever faced impeachment before?

Only once, in 2004, when President Roh Moo-hyun was accused of calling on voters to support his party in parliamentary elections. The calls were said to violate a law requiring the president to remain neutral in the election.

The National Assembly voted for impeachment, but the decision enraged many South Koreans, who demonstrated in large numbers and gave Mr. Roh’s party a landslide victory at the polls. The Constitutional Court voted against impeachment, saying Mr. Roh’s breaches of the election law were relatively minor, and he was returned to office.

Who is Choi Soon-sil?

She is the daughter of a cult leader who befriended Ms. Park in the 1970s, when Ms. Park was a young woman and her father, Park Chung-hee, was South Korea’s dictator. Lurid rumors about Ms. Park’s connection to the Choi family have dogged her for years, and many have come to believe that Ms. Choi wields a sinister, cultlike influence over the president.

Ms. Choi was arrested and charged with extortion and fraud, and prosecutors said they considered Ms. Park an accomplice.

Though Ms. Park cannot be indicted while in office, prosecutors can pursue charges against her if she is removed from office or after her term ends in February 2018. The Constitution limits presidents to one term