Opposition leader Lee Jae-myung appeared in court Tuesday for a hearing to decide whether to issue an arrest warrant for him over corruption charges, the biggest crisis yet for the former presidential candidate.

The Seoul Central District Court is expected to make a decision as early as Tuesday night if the hearing proceeds as scheduled.

Leaning on a walking stick, the frail-looking Lee walked slowly and unsteadily as he entered the court without answering a barrage of questions from reporters.

Hundreds of supporters and protesters lined the road to the court, holding up placards reading "Lee Jae-myung is innocent. Reject the arrest warrant," or "Suspect Lee Jae-myung is the ringleader."

The hearing came three days after Lee, chair of the main opposition Democratic Party, pulled out of his hunger strike launched on Aug. 31 in protest of what he claimed the "incompetent and violent" government of Yoon Suk Yeol.

It marks the first time that a main opposition party leader has appeared in court for an arrest warrant hearing.

Lee has been accused of breach of trust, bribery and other charges stemming from his time as mayor of Seongnam, south of Seoul, years ago in connection with a scandal-ridden land development project and his alleged involvement in a company's illegal cash remittance to North Korea.

The prosecution accuses Lee of committing breach of trust worth 20 billion won (US$15 million) by giving special treatment to a private developer in the Baekhyeon-dong district apartment project in the city of Seongnam, south of Seoul, between 2014 and 2015, when he was serving as the city's mayor.

Lee is also suspected of asking Ssangbangwool Group, an underwear maker, to illegally transfer $8 million to North Korea between 2019 and 2020, when he was serving as Gyeonggi Province governor, through his deputy to facilitate his visit to the North, and push for a joint smart farm project between his province and Pyongyang.

Should the court issue the warrant, it would deal a serious blow to Lee's leadership, but if the court rejects the warrant request, it would bolster Lee's standing in the party and lead to a massive blowback against the government.

By law, sitting lawmakers are immune from arrest while parliamentary is in session unless the National Assembly passes a motion giving its consent to the arrest, a measure intended to shield lawmakers from political persecution.

Last week, the National Assembly voted to lift the opposition leader's arrest immunity in a surprise, narrow 149-136 vote attributed to a number of dissenting ballots from his own party that commands a majority of parliamentary seats.

The DP has vehemently lambasted the motion as the government's attempt to "kill a political enemy" eight months before the general elections.

In February, the parliament had voted to reject the government's first request for consent to arresting the DP leader by a margin of only one vote.

Lee has been under medical treatment since he was hospitalized on Sept. 18 due to deteriorating health during his hunger strike. He has been put on treatment for recovery after ending the hunger strike on its 24th day on Saturday. (Yonhap)