The main opposition Democratic United Party (DUP) was set to pick its new leadership at a national convention Saturday ahead of this year's presidential race.

Party sources said that Reps. Kim Han-gil and Lee Hae-chan were in the lead for the top post as the party gathering got underway at the KINTEX convention center, northwest of Seoul.

They added that Kang Gi-jung, Choo Mi-ae, Woo Sang-ho and Cho Jung-sik were trailing the leaders and will compete for the five seats on the party's supreme council.

As of Saturday afternoon, Kim had pulled ahead in regional party races, followed by the former prime minister Lee, who had been considered the favorite before the race began.

Kim won eight of the 10 regional races accounting for about 13 percent of all votes that will be cast to pick the party leadership, with Lee securing two victories. The difference between the two candidates, however, stood at just 210 votes with voters from the country's most populous regions still casting ballots.

Political watchers said that Seoul and the Gyeonggi region, which is home to more than half of the country's 49 million people, will decide the outcome of the election.

The winner will take charge of the party and set up a strategy for the critical presidential race slated for December 19. At present, former ruling Saenuri Party chairwoman Park Geun-hye is in the lead after pulling off an upset victory in last month's parliamentary elections.

Under Park's leadership the Saenuri Party won 152 seat out of the 300 seats up for grabs, with the DUP winning 127.

(Yonhap News)