An official monitors security camera screens showing locations designated for ballot box storage at the election situation room of the National Election Commssion in Gwacheon, Gyeonggi Province, Tuesday, one day prior to the general election. (Im Se-jun/The Korea Herald)

South Korea is poised to confront a pivotal moment Wednesday as much of the nation prepares to cast their votes for 300 new members of the National Assembly, in an election that will not only shape the political landscape of the country for the next four years but also serve as a crucial test for the president, who is currently a conservative.

On the eve of the quadrennial Election Day, the rival parties fanned out to critical battleground districts Tuesday, making last-minute efforts to woo voters on the eve of the parliamentary elections.

The move comes as the ruling People Power Party and the main opposition Democratic Party of Korea have locked horns to secure the majority of seats in the 300-member National Assembly. The outcome could turn President Yoon Suk Yeol into a lame duck leader.

People Power Party interim leader Han Dong-hoon visited Seoul’s central Gwanghwamun area in a last spurt of campaigning before Wednesday’s election.

“We ask for (our voters) to give us the least number of seats required to fend off the atrocious and shameless main opposition party,” Han said in a written statement for voters released ahead of his visit.

“For the past two years, our government and the ruling party have suffered due to the main opposition’s attempt to (stop us). They have attempted to tarnish the reputation of our government through fake news and false propaganda, while obstructing efforts to achieve stronger diplomacy and reform,” he added.

Han criticized the main opposition party's attempt to win “200 seats in the National Assembly,” while emphasizing several of the main opposition candidates’ corruption scandals.

Democratic Party Chair Lee Jae-myung also made one of his final appeals to voters before heading into a court hearing at the Seoul Central District Court in the morning. Lee is accused of multiple corruption charges from when he was in office as the mayor of Seongnam, a satellite city south of Seoul, from July 2010 to March 2018.

“I ask voters to please make sure to vote and exercise your sovereignty to judge this administration's failures and clearly show a warning. Please make sure to deny the majority of seats (in the assembly) to the political forces that have betrayed the people," said Lee, who himself is running again to represent Incheon’s Gyeyang-B constituency.

The main opposition leader criticized the Yoon administration’s “failure to tame food prices” and for “ignoring its tasks concerning the livelihood of the people.”

Of a total of 44.28 million eligible voters here, some 30.34 million have yet to cast their ballots, according to the watchdog National Election Commission.

Lee was set to head to Seoul’s central Yongsan-gu area, one of the key swing districts here, in the final leg of election campaigning.

In recent days, several opposition politicians have mentioned obtaining a majority of “200 seats” in the National Assembly as their goal, while ruling party and conservative candidates claimed it would be a worst-case scenario if their respective rivals were to achieve such a milestone.

Rebuilding Korea Party leader Cho Kuk warned Monday that if "the Democratic Party and Rebuilding Korea Party combined” manage to clinch “200 seats,” then they will work to bring first lady Kim Keon Hee -- who is currently mired in stock manipulation involvement allegations and an anti-graft law violation scandal -- to court.

Ihn Yo-han, election campaign head of the People Future Party, a satellite party of the People Power Party, railed against this idea during a press briefing Tuesday by claiming that if the opposition parties combined achieve such feat, it could “cause chaos in the country.”

Observers say that if the main opposition secures the 200-seat majority in the assembly, then they could begin procedures to impeach Yoon or push for a constitutional amendment.

Meanwhile, if the ruling People Power Party secures the majority, it could empower Yoon’s initiatives to boost the economy, push for labor law reforms and strengthen trilateral security cooperation with the US and Japan.

The sum of voters' decisions on Wednesday will determine the 300 members of the National Assembly, with 254 seats to be allocated via voters directly electing their constituency representative and the remaining 46 via voters choosing a party to be allocated seats through proportional representation.