The day of decision has arrived for Korean voters after a messy race punctuated by mudslinging between the two main political parties.

Voting to elect 300 members of the parliament will begin at 13,470 polling stations nationwide at 6 a.m. Wednesday, with more than 40 million people eligible to cast ballots. Polling stations will close at 6 p.m.

Of the 300 seats, 246 are to be elected directly from precincts and 54 through proportional representation.

A total of 927 candidates are vying for the 246 electorate seats, yielding an average of 3.8 candidates per seat. The competition rate is lower than the preceding election’s 4.3:1, in part due to the alliance formed by the two liberal opposition parties ― the Democratic United Party and the Unified Progressive Party.

For the main parties, the stakes in Wednesday’s poll go beyond control of the next parliament for the next four years.

The ballot comes just eight months before another election to pick the successor to President Lee Myung-bak. The results will therefore hugely influence the dynamics of the presidential race, pundits say.

A few months ago, the largest opposition DUP was seen as likely to crush the Saenuri, capitalizing on public dissatisfaction with the conservative president.

The race, however, has turned out to be a nail-biter, as the Saenuri managed to bounce back in popularity while the DUP failed to extend its early lead. Political analysts now say the election is likely to be one of the closest in recent memory, allowing neither of the two parties a majority.

Aside from parliamentary seats, Wednesday’s elections are to determine several other elected posts in some areas. In Sejong, a new administrative city south of Seoul, citizens will pick their first mayor and education superintendent, while Incheon will vote for a ward chief and local council members.

Preliminary results, except for those precincts with tight races, are expected before midnight, according to the National Election Commission.

By Lee Sun-young (milaya@heraldcorp.com)