SEOUL, South Korea - The former Hyundai CEO, now the front-runner in South Korea's presidential election, denied involvement yesterday in a stock-manipulation case, accusing his opponents of spreading lies that he said would not derail his bid for office.

Lee Myung Bak appeared headed for easy victory in today's vote, on his 66th birthday. Lee, the candidate of the main conservative Grand National Party, has said he will abandon the presidency if he is found to be involved in financial irregularities.

After Lee amassed huge leads in opinion polls for months, his campaign suffered a blow when the National Assembly voted Monday to approve an independent investigation of him in the stock-manipulation case.

Lee, a former Seoul mayor, said at a news conference yesterday: "Those who abused the legal system and their power will face a large backlash. Even if they investigate me 10 times or 100 times, the results will not change."

Lee's popularity is attributed to the perception that he can inject new life into the economy after what has been viewed as a lackluster performance under liberal President Roh Moo Hyun.

"Have you been happy over the past five years?" Lee asked more than 1,000 cheering supporters during a rally in Seoul. "If we have a capable leader, we won't be afraid of Japan and China, and we can move forward even though the world economy is in a difficult situation."

The latest development in the financial allegations surfaced after the liberal United New Democratic Party publicized a video Sunday showing Lee saying in 2000 that he founded the firm at the center of a stock-manipulation case. A Korean American who was Lee's former business associate has been indicted in the case. Lee has said the comments were taken out of context and he denied the allegations.