South Korea's two main presidential candidates made their final campaign stops Tuesday, just a day before the presidential election that observers say is still too close to call.

Park Geun-hye of the conservative ruling Saenuri Party is making stops at the southeastern city of Changwon, the southern port city of Busan and the central city of Daejeon, a top swing voting city, before her final campaign appearance in Seoul.

"I will restore the middle class and expand it to 70 percent of the country," the 60-year-old daughter of South Korean dictator Park Chung-hee said during a press conference at the party headquarters in Seoul.

Her archrival, Moon Jae-in of the center-left main opposition Democratic United Party, headed to the central cities of Cheonan and Daejeon and is scheduled to make a last stop in Busan, a conservative stronghold where he earned his first parliamentary seat earlier this year.

"It has been proved that the Saenuri Party is incapable of representing the country," the 59-year-old former human rights lawyer said in a separate press conference, criticizing Park and incumbent president Lee Myung-bak.

Opinion surveys released last week showed Park maintained a slight lead over Moon, but the gap was well within the margin of error in most polls.

While analysts say the outcome of the contest would depend on voter turnout, both Park and Moon claim to have an edge over the other.

Higher voter turnout, observers say, signals young people turn out in big numbers, which is likely to be a tailwind for a liberal candidate. The National Election Commission reportedly expects voter turnout to be around 70 percent.