South Korea has long been plagued by ideological rifts over how to deal with its communist neighbor since the 1950-53 Korean War ended in a cease-fire, not a peace treaty.
In staunchly anti-communist South Korea, conservatives usually attack liberals for their alleged sympathy toward North Korea ahead of elections. The North Korean influence has often swayed the results of polls in South Korea.
Cho Yoon-sun, a spokeswoman of the conservative ruling Saenuri Party, recently accused alleged pro-North Korean liberal politicians of trying to become lawmakers.
Cho Yoon-sun of the Saenuri Party (Yonhap)
She said the liberal politicians shed tears after hearing a New Year's message by North Korea's founder Kim Il-sung, the late grandfather of current leader Kim Jong-un.
She also claimed that they held a party meeting after paying a tribute to the late Kim's portrait. She did not give the date of their alleged tribute to Kim and other specific details.
The accusations came after the minor opposition Unified Progressive Party (UPP) fielded Lee Sang-kyu, a liberal candidate who the ruling party claims came from a political movement that showed support for the North, in Seoul's Gwanak B district. Lee's candidacy was announced after UPP co-chairwoman Lee Jung-hee quit her candidacy in the southern Seoul district after revelations that her staff had rigged a telephone survey during a district primary.
Lee Sang-il, another spokesman of the ruling Saenuri Party, also said he is concerned about what could happen if liberal politicians become lawmakers. He said liberal politicians denied North Korea's involvement in the deadly sinking of a South Korean warship.
Lee, the liberal candidate, was not immediately available for comment.
Forty-six South Korean sailors were killed in the sinking of the Cheonan warship near the two Koreas' western sea border in March 2010, heightening tensions on the Korean Peninsula.
In 2010, a team of multinational investigators concluded that a North Korean torpedo was responsible for the sinking. However, the North still adamantly denies its involvement, a claim supported by some South Koreans.
Lee Yong-sup of the Democratic United Party (Yonhap)
Meanwhile, Lee Yong-sup, a chief policymaker of the main opposition Democratic United Party, lashed out at the ruling party for causing confusion among people with outdated red-baiting tactics.
The Unified Progressive Party also said the ruling party's red-baiting tactics are a political conspiracy to destroy an alliance between the two opposition parties to field unified candidates to boost their chances in the elections.
South Korea's ruling conservative parties have a history of benefiting from the influence of North Korea.
A few weeks before the 1987 presidential election, a Korean Air plane from Baghdad to Seoul exploded in mid-air near Burma. All 115 people on board were killed.
A North Korean female agent, Kim Hyun-hui, was arrested after she got off the Boeing 727 during its refueling stop in Bahrain and was later extradited to Seoul just before the election, which critics said was a ploy aimed at boosting the chances of the then ruling conservative government at the polls.
In 1996, the then conservative ruling New Korea Party again swept parliamentary elections after North Korean soldiers mysteriously staged illegal military maneuvers at the border village of Panmunjom for three days in a row.
South Koreans are sensitive to military tension with North Korea and tend to rally around conservatives.
On Tuesday, North Korea said it will go ahead with its planned rocket launch between April 12 and 16 to put a satellite into orbit in defiance of successive warnings from global leaders attending a nuclear summit in Seoul.
Still, opinion polls have suggested that the ruling and opposition parties are expected to win about 130 each out of 300 parliamentary seats in the elections.