Lee Jae-myung, center, leader of the main opposition Democratic Party of Korea, speaks to reporters following his first trial for election law violation at the Seoul Central District Court in Seocho District, Seoul, Friday. Yonhap

A Seoul court sentenced opposition leader Lee Jae-myung to one year in prison, suspended for two years, Friday, after finding him guilty of lying during his presidential campaign.

If upheld by the Supreme Court, Lee, leader of the main opposition Democratic Party of Korea, will lose his parliamentary seat and be barred from running in the 2027 presidential election.

The Seoul Central District Court found Lee guilty of making false statements, violating the Public Official Election Act.

The court sentenced Lee to one year in prison, suspended for two years, ruling that his disputed statements constituted false information.

In its decision, the court emphasized that spreading false information during an election can distort and undermine the democratic will of voters. It also noted that Lee's remarks gained widespread attention through the media, particularly as the suspicions against him were of significant public interest.

"In the event false statements are made to voters during an election, public opinion can be distorted and damaged," the court said, noting Lee's statements were far-reaching as they were broadcast by the media.

Lee has denied all allegations, calling the ruling difficult to accept, and said he will appeal the decision.

Prosecutors said Lee spread false information on two occasions.

One came during a media interview on Dec. 22, 2021, when Lee said he did not know Kim Moon-ki, a former executive at Seongnam Development Corp., while serving as mayor of Seongnam, a city in Gyeonggi Province.

Kim, who played a pivotal role in a development project in the city that later became embroiled in a corruption scandal, is believed to have held critical information related to alleged preferential treatment connected to the project. Kim died in 2021.

The second charge stems from a parliamentary audit of the Gyeonggi provincial government in October 2021. He said the Ministry of Land, Infrastructure and Transport pressured him to rezone the former site of the Korea Food Research Institute in Seongnam.

The site was later developed into apartment complexes by a real estate builder, sparking accusations that Lee's decision to rezone the land granted the company preferential treatment.

This ruling marks the first verdict in more than two years since Lee was indicted without detention in September 2022, and the first sentence among his four ongoing trials.

Under Korean law, elected officials lose their posts and are barred from running in elections for five years if they are fined more than 1 million won ($713) for violating election laws or sentenced to prison for other crimes.