South Korean party chiefs Tuesday made their final appeals to voters before a closely contested parliamentary election, a key test of sentiment in the run-up to December's presidential poll.
"It's time to judge the current regime!" opposition leader Han Myeong-Sook, clad in her party's signature yellow jacket, urged the public in Seoul's Songpa district.
"Allow us to end the Lee Myung-Bak administration and give you spring," she said.
Wednesday's vote is seen as a referendum on President Lee's term in office, and an indication of whether his successor can retain the powerful presidency for the conservatives in eight months' time.
Presidents serve a single five-year term and parliaments are elected for four years. This will be the first time in two decades that the votes fall in the same year.
Lee's New Frontier Party (NFP) had 165 seats in the outgoing parliament against 89 for the main opposition centre-left Democratic United Party (DUP), but Wednesday's vote is seen as too close to call.
Opinion polls are banned this week but experts quoted Monday by Yonhap news agency predicted a dead heat, with each side winning 130 seats in the 300-member National Assembly.
Interim NFP leader and likely presidential candidate Park Geun-Hye depicted the DUP as socially divisive and bent on dismantling a decades-old security alliance with the United States.
"The opposition is recklessly trying to dump the free trade agreement with the US and to shatter the Korea-US alliance," she told a street rally in Seoul.
"We're the only one who can stop their dangerous drive!" Park told hundreds of cheering supporters -- mostly middle-aged or elderly -- who chanted her name and gave her every remark thunderous applause.
Park, the daughter of assassinated strongman Park Chung-Hee, admitted the ruling party has "let people down too often" with failed policies but urged voters to give it a second chance.
"Tomorrow is the day. Vote for us, and we will never let you down again," Park said, waving her injured right hand -- wrapped in bandages due to too many handshakes.
Park Hyang-Sook, a 52-year-old businesswoman and longtime DUP supporter, said she had recently changed heart and would vote for the conservatives because she trusts them on security issues.
"There are certain lines not to be crossed regarding our national security, given we still have North Korea up there," she said.
North Korea plans to launch a rocket between April 12 and 16. But livelihood issues -- rising prices, high education and housing costs, job difficulties, a widening income gap and a weak welfare system -- are the key election topics.
Both parties pledge to expand state welfare and tighten controls over the mighty conglomerates, or chaebol, which dominate the economy and are accused of stifling small business.
The NFP backs the recently ratified free trade agreement with the United States, while the DUP vows to renegotiate it.
In the run-up to the election, the NFP ditched its old name of the Grand National Party along with many former legislators to try to shed its image as a party for the rich.
Given a strong generational divide, with younger people largely backing the opposition and older electors supporting the conservatives, turnout will be closely watched to see if the DUP can mobilise the youth vote.
Twitter and other social networks may play a major role in this, as they did last October when an opposition-backed candidate defeated a conservative opponent to win the Seoul mayoral race.
Some 246 legislators will be directly elected on Wednesday and another 54 through proportional representation. About 40.18 million people are eligible to vote.