Rep. Lee Jae-myung, leader of the main opposition Democratic Party of Korea, speaks during a press conference at the National Assembly in Seoul, Sunday. Newsis

After being convicted of violating the election law and being handed a suspended prison term only four weeks ago, Rep. Lee Jae-myung, leader of the main opposition Democratic Party of Korea (DPK), faced a bleak political future. If the ruling stands, he will be stripped of his National Assembly seat as well as the opportunity to run for president in the next election.

But then, an incredible political scenario unfolded for Lee. In what critics call a self-destructive move, President Yoon Suk Yeol suddenly imposed martial law on Dec. 3, which baffled even Yoon's most ardent defenders and prompted lawmakers to vote to impeach him.

Now, Lee stands as a clear favorite to win the next presidential election, which could be held early next summer. By law, the Constitutional Court is required to decide whether to uphold the impeachment in 180 days — and if it rules against Yoon, a presidential election must be held in the next 60 days.

Lee is a heavy favorite to win. In a survey released on Thursday by pollster Embrain Public, 37 percent of 1,005 respondents picked Lee, with other potential rivals lagging far behind.

Only 7 percent chose Han Dong-hoon, leader of the ruling People Power Party, followed by 6 percent for Cho Kuk, former leader of the minor liberal opposition Rebuilding Korea Party. After the Supreme Court upheld his convictions of academic fraud involving his children and illegal interference with a government inspection last week, Cho is banned from running for public office for seven years. This could mean additional liberal support for the DPK leader.

But it is still premature to conclude that everything will turn out fine for Lee, with many challenges and variables to consider in the coming months, experts say.

“At the height of former President Park Geun-hye's impeachment crisis, her approval rating was 5 percent and her party's was 17 percent, a Gallup Korea poll showed. The figures were far lower than Yoon's current approval rate of 11 percent and 24 percent for his party,” Shin Yul, professor of political science at Myongji University, told The Korea Times. “This suggests that many don't see the DPK as a reliable alternative and that new challengers could emerge if the election is indeed taking place.”

Shin said he believes Han appears to be the only conservative contender with a serious chance of winning. But fresh challengers could still arise from the liberal bloc, he noted.

“Woo Won-shik, speaker of the National Assembly, is one of them. He is gaining popularity currently not because the president was impeached under his watch, but because he led the effort to prevent (what many view as Yoon's) self-coup attempt,” Shin said.

In a Gallup Korea poll released on Friday, Woo was selected by 56 percent of respondents as a politician they trust the most over Lee at 41 percent and Han at 15 percent.

Han Dong-hoon, leader of the ruling People Power Party, walks toward a meeting room after lawmakers voted to impeach President Yoon Suk Yeol at the National Assembly in Seoul, Saturday. Yonhap

The legal risks Lee faces are another important factor. Under the Supreme Court's guidelines, the trial for his election law violation is expected to finish in six months. If it is upheld by the appeals and the top court, he will be banned from running for public office for 10 years. This would mean a de facto end to the 61-year-old's political career. In addition to the trial, he is facing four other lawsuits on charges of instigating perjury and corruption.

At Sunday's press conference, Lee called on justices at the Constitutional Court to expedite the process for Yoon's impeachment trial to minimize social and political confusion.

He then proposed a consultative body through which the executive and legislative branches of government can work together for the stability of state affairs. He also said his party would not impeach Han Duck-soo as the nation's acting president, at least for now.

“The truth and accountability for this outrageous case should be uncovered in order to hold those responsible accountable and prevent it from happening again. I call for a fast, rigorous and thorough investigation to find the truth,” Lee said. “Those who played their roles in the insurrection (martial law) should cooperate with the investigations. Don't forget that the whole country is watching.”

Later that day, Rep. Kweon Seong-dong, the ruling party's floor leader, said he will not accept the consultative body proposal.