The main opposition Democratic Party (DP) is set to elect its new leadership on Sunday, with former Chairman Lee Jae-myung almost certain to win the race for a second term.

The DP kicked off its national convention at 1 p.m. at the KSPO Dome in southern Seoul in order to elect a new chair and five members of the party's Supreme Council.

The new leadership will be elected based on the combined results of 17 rounds of primaries, a survey of the general public and online polls by party representatives, which will account for 56 percent, 30 percent and 14 percent, respectively.

The outcome will be released after 6 p.m. Sunday.

In the 17 rounds of primaries held from July 20 to Saturday, former DP chair Lee secured nearly 90 percent of the combined ballots cast by registered party members.

Rep. Kim Min-seok is in the lead among eight candidates in the race to elect five Supreme Council members.