SEOUL - South Korea's Supreme Court on May 1 overturned an earlier ruling that had cleared election frontrunner Lee Jae-myung of election law violation, throwing into doubt his eligibility to run for the presidency.

Lee, the candidate of the liberal Democratic Party which controls Parliament, leads opinion polls to win a snap presidential election sparked by former conservative president Yoon Suk-yeol's ouster over his imposition of martial law.

The election law violation case against Lee had been closely watched since a ruling that removes him from the ballot could further deepen divisions in society, after months of political turmoil that has hampered efforts to steer Asia's fourth-largest economy through the choppy waters of US tariffs.

In March, an appeals court had cleared Lee of violating the election law, but prosecutors had appealed the decision to the Supreme Court.

ALSO READ: South Korea officials heading to Washington for talks over US tariffs

Lee is embroiled in several criminal trials, but the election law case was in the spotlight because if the Supreme Court overturned Lee's not guilty verdict and it is finalised, it would bar him from contesting elections for at least five years.

The Supreme Court said that Lee violated election law by publicly stating false facts and ruled to send the case back to the appeals court.

While the Supreme Court moved unusually fast to consider Lee's election law case, it gave no deadline for the lower court, which usually takes months to revisit rulings and it was unclear if it would come before the June 3 election.

Yes, I would also like to receive SPH Media Group's SPH Media Limited, its related corporations and affiliates as well as their agents and authorised service providers. marketing and promotions.

Meanwhile, South Korea's acting leader Han Duck-soo is expected to resign on May 1 in order to clear a path for him to join the race to become the country's permanent president, the Yonhap News Agency reported.

Prime Minister Han looks set to contest the election so he can leverage his higher profile since being thrust into the top post after the removal from office of former President Yoon.