SEOUL — South Korea’s conservative People Power Party (PPP) moved Saturday to replace its presidential nominee Kim Moon Soo with former Prime Minister Han Duck-soo, a dramatic reversal that reflects mounting internal discord following the impeachment of ex-President Yoon Suk Yeol.

The party’s emergency committee nullified the result of its May 3 primary and registered Han as its new presidential candidate, just one week after Kim won the nomination with 56.3% of the vote.

The decision came after days of behind-the-scenes pressure on Kim to step aside amid concerns over his electability against Democratic Party frontrunner Lee Jae-myung.

Kim, a former labor minister under Yoon and an outspoken conservative, condemned the move as an “overnight political coup,” vowing to challenge the decision through legal and political channels.

He filed an injunction Saturday in an attempt to block the party from formally canceling his nomination.

Han, who served as acting president after Yoon’s impeachment in December and official removal in April, resigned from office on May 2 to launch a presidential bid.

He has positioned himself as a steady and experienced leader capable of guiding the country through a period of economic uncertainty and diplomatic tension, especially amid strained U.S.-Korea trade relations under President Donald Trump.

In a televised statement, Han appealed for party unity. “Unifying the candidacies is the will of the people,” he said. “We must move forward together for the sake of our economy and our future.”

Kim rose in popularity among the PPP’s hardline base after refusing to participate in a collective apology demanded by opposition lawmakers over Yoon’s failed attempt to impose martial law on December 3 — an act that led to the president’s impeachment by the National Assembly 11 days later.

Han and Kim were unable to reach an agreement to consolidate their campaigns, prompting the party’s emergency committee to act unilaterally. Han’s candidacy still requires ratification through a party-wide vote Saturday and final approval by the PPP’s national committee on Sunday — the same day as the candidate registration deadline for the June 3 election.

Meanwhile, Democratic Party candidate Lee Jae-myung continues to lead in opinion polls. Lee, who spearheaded the impeachment drive against Yoon, dismissed the PPP's infighting. “I’ve heard of forced marriages, but never forced unity,” he said.

Lee, known for his anti-establishment messaging and promises to tackle inequality, is a polarizing figure. He currently faces five criminal trials on corruption and related charges, which would be suspended if he wins the presidency due to South Korea’s immunity laws for sitting presidents.

The conservative party’s internal shake-up highlights the fragile political landscape just weeks ahead of the national vote, in what observers say could become one of South Korea’s most unpredictable elections in decades. — Agencies