South Korea's presidential front-runner Lee Jae-myung enters leadership race

By Ju-min Park

SEOUL (Reuters) - South Korean opposition leader Lee Jae-myung, who is the front-runner in opinion polls to be the country's next leader, declared his bid for the presidency on Thursday, promising to fix inequality and spur economic growth.

The presidential election will be held on June 3, after the impeachment of former president Yoon Suk Yeol for his December martial law declaration was upheld on April 4.

In a video released on Thursday, Lee pledged to fix economic polarisation that he said was a key source of social conflict, highlighting how he felt this had exacerbated the recent political turmoil in the wake of Yoon's martial law order.

He vowed to drive large-scale investments at the government level in technology and talent development to resuscitate economic growth.

Lee, who has sought to brand himself as a pragmatist, said it did not matter who launched a policy but what was important was whether the policy was useful.

Conservative critics have warned that the opposition could undermine the alliance with the United States and threaten improved ties with Japan, but Lee proposed a pragmatic approach to diplomacy.

"Realistically speaking, the South Korea-U.S. alliance is important, and South Korea, U.S., Japan cooperation is important. Within that, the consistent principle is the national interest of the Republic of Korea is the top priority," Lee said.

A new South Korean leader will likely face the daunting task of negotiating with the U.S., the country's leading security ally, over tariffs that have cast a cloud over the export-reliant economy.

Lee, 61, lost by the slimmest margin in the country's history when he ran against Yoon in the 2022 presidential election.

But last year, he led his liberal Democratic Party to a landslide victory in a parliamentary election, and enjoys strong support from liberal voters.

On Wednesday, Lee stepped down as leader of the main opposition party, preparing to switch gears to focus on his election campaign.

A Gallup poll announced on April 4 put Lee as the favourite to become the next president with 34% support, versus 9% for the top conservative contender, 73-year-old former labour minister Kim Moon-soo.

The conservatives have a wide-open presidential field. The ruling People Power Party (PPP) plans to confirm its candidate through a primary in May.

Han Dong-hoon, a former PPP leader, plans to announce his run for president later on Thursday. Once close to ousted leader Yoon, Han turned against him and supported Yoon's impeachment.

Meanwhile, Lee still faces legal uncertainties that could affect his candidacy.

He is on trial for charges ranging from alleged bribery to involvement in a $1-billion property development scandal. Prosecutors have also appealed against a court's decision in March to overturn Lee's guilty verdict on election law violations.

It was unclear if any of the ongoing court cases would present a roadblock to Lee's presidential bid.

In January 2024, Lee survived a knife attack and underwent surgery when he was stabbed in the neck by a man during an event.

(Reporting by Ju-min Park, Joyce Lee; Editing by Ed Davies and Saad Sayeed)