SEOUL -- As South Korean political parties gear up for the presidential election slated for March 2022, key candidates have been preoccupied with attacking each other in bitter smear campaigns.

Bearing the brunt of these negative political campaigns are two leading candidates: Gyeonggi Province Gov. Lee Jae-myung, who is seeking nomination for the ruling Democratic Party, and former Prosecutor General Yoon Seok-youl, who hopes to be the candidate of the conservative People Power Party.

Local media are running stories almost daily about the latest scandals involving the two hopefuls, rather than focusing on key policy issues.

Lee has now become embroiled in a potential embarrassment concerning a development project in Daejang-dong, a suburb of Seoul.

While serving as mayor of the city, Lee converted the private-sector project into one led by the local government and chose the contractor through a competitive bid. One of the companies in the consortium that won the contract was owned by a retired journalist close to Lee. The firm profited nicely on only a small investment, according to local media. Now, a People Power Party candidate has jumped on the issue, raising allegations that Lee's son landed a job at a company involved in the project.

The allegations may offer an opportunity for former Prime Minister Lee Nak-yon -- Lee Jae-myung's less popular rival in the Democratic presidential primary -- to narrow the gap with the Gyeonggi Province governor, who is leading in polls. The former prime minister said on Sept. 13 that he is watching the allegations "with interest."

Democratic Party hopeful Lee Jae-myung speaks to a crowd at a voting site during a preliminary presidential poll in North Chungcheong Province on Sept. 5. (Photo by Sotaro Suzuki)

On the following day, Yoon, the front-runner for the People Power Party's nomination, demanded that the newly established Corruption Investigation Office for High-ranking Officials investigate the allegations.

On Sept. 14, Gov. Lee held a news conference denying the allegations. The project was originally promoted by public developer Korea Land and Housing but was transferred to the private sector through an illegal lobbying campaign, he claimed. As then-mayor, Lee handed the project back to the public sector, he said. "It is a model public project that yielded 550.3 billion won ($466 million) in revenue from the project to the local people" by supplying rental housing and the development of parks, Lee said.

As for the money earned by the company run by the retired journalist, Lee stressed the allocation of profits was the consortium's internal matter, with input from the municipal government. He also denied the allegations concerning his son's employment.

Meanwhile, counterpart Yoon is facing allegations of abuse of power as the top prosecutor. Prior to the parliamentary election in April last year, senior prosecutors asked a person linked to the opposition party to file criminal complaints against ruling party politicians and media figures who were campaigning for prosecution reform. The opposition party later filed criminal complaints partly in line with the request from prosecutors.

While the link between the request and the opposition party's legal action is not clear, a citizen group has filed a criminal complaint accusing Yoon of abusing authority and leaking official secrets. In response, the Corruption Investigation Office for High-ranking Officials has started investigating Yoon on four related charges, including abuse of power.

In a Sept. 8 news conference, Yoon categorically denied the charges. "I warn those who work on similar political maneuvering in the future that they need to prepare well before doing so," he said. A clearly angry Yoon called on the National Assembly to summon him over the matter, saying he will answer all questions.

Former Prosecutor General Yoon Seok-youl visits Daegu, a largely conservative city in southeastern South Korea on Sept. 11. (Photo by Yosuke Onchi)

Smear campaigns loaded with untruths sometimes work well in South Korea and can dramatically change the dynamics of an election. One such example is the scandal that destroyed the campaign of Lee Hoi-chang, a conservative politician in the 2002 presidential election.

As the candidate for the then-Grand National Party, a forerunner of the People Power Party, Lee was widely seen as the favorite in the race. But his poll ratings plunged after someone close to the ruling Democratic Party claimed that two of his sons had been excused from mandatory military service because of his political status.

Exempting members of prominent families from the up-to-three-years obligatory military service that South Korean men face is a hot-button issue because of its obvious nepotism. But an investigation by prosecutors found that the allegations were unfounded before the election. Lee nevertheless lost to his Democratic contender, Roh Moo-hyun, as the smear clung to him throughout the campaign.

But this tactic did not work in the 2007 presidential election. Lee Myun-bak, candidate for the Grand National Party, was charged of corruption by the ruling party. He managed to maintain his political momentum and went on to win the presidency in an election that returned conservatives to power for the first time in a decade.

South Korean voters seem to be less sensitive to complex corruption charges against candidates than to allegations involving more emotionally charged issues, such as military service, education and other family-related matters.

Gov. Lee Jae-myung bristled when he was asked about an alleged extramarital affair during a debate among ruling party presidential hopefuls. Yoon, the former chief prosecutor, is also under fire over some family issues, including allegations of plagiarism related to a doctoral thesis written by his wife.

Former Prime Minister Lee Nak-yon is running a campaign aimed at drawing a contrast between his squeaky clean image and the tarnished perceptions of party rival Lee and Yoon. The former prime minister is trying to cast himself as a "safe" candidate who has a better chance of winning the presidency.

A woman who voted for the former prime minister on Sept. 5 in the local primary in Cheongju, capital of North Chungcheong Province, said: "I want to see a person I, as a mother, do not feel ashamed of to be elected president."

But presidential hopefuls are under increasingly dirty political mudslinging that is diverting attention away from fundamental policy differences.

Lee Myung-bak, right, attends the inauguration ceremony of President Park Geun-hye in February 2013. (File photo by Kyodo)

Conservative daily news outlet JoongAng Ilbo recently denounced the sordid landscape of the presidential race as it recalled the 2007 election, in which Lee Myung-bak and Park Geun-hye -- both conservative politicians who later went assumed the presidency -- clashed in the opposition Grand National Party's primary.

While dirty tactics were common in the 2007 presidential run-up, the candidates did not neglect assessing and analyzing issues in detail, the newspaper contended. In contrast, the current presidential race is marked by an extreme lack of "policy vision" and "a total lack of understanding the spirit of the times" on both the ruling and opposition sides.

"The level of presidential elections has been sinking over time," it said.

How the presidential race is panning out does not bode well for South Korea, which is facing a raft of tough policy challenges, including a growing income gap, dismal employment situation, uncertain response to U.S.-China tensions and a deeply strained relationship with Japan. Whoever is elected president next March will have no time to waste in tackling these sticky challenges.