The main opposition People Power Party (PPP) was set to pick its presidential nominee Friday as the two leading contenders appeared locked in a tight race.

The nominee will be announced at a national convention at the Kim Koo Museum and Library in Seoul following a four-day poll of party members and the general public on who is best prepared to take on Lee Jae-myung, the nominee of the ruling Democratic Party.

The four candidates in the PPP primary are former Prosecutor General Yoon Seok-youl, Rep. Hong Joon-pyo, former Rep. Yoo Seong-min and former Jeju Gov. Won Hee-ryong, with Yoon and Hong projected to have near-equal chances at winning the nomination.

Yoon is believed to have the backing of more party members, while Hong has more support among the general public.

The winner of the primary will be determined after combining the votes of party members and the public by a 50:50 ratio. The candidate with the most votes will take home the nomination, and there will be no runoff.

Friday's event will mark the end of the third and final round of the primary.

The winner is scheduled to give an acceptance speech and then hold a press conference to announce his political vision.

Key deciding factors in the outcome are expected to be generation and region, with the votes of young people in their 20s and 30s living in the capital area seen as competing against those of the party's traditional support base, who are in their 50s and 60s, and based in the southeastern city of Daegu and North Gyeongsang Province.

In a reflection of the high public interest in the race, a record 63.89 percent of the PPP's nearly 570,000 members who are qualified to vote took part in the four-day polling, according to the party.

The March 9 presidential election has shaped up to be a four-way race involving Lee, the eventual PPP nominee, Ahn Cheol-soo of the minor opposition People's Party and Sim Sang-jeung of the minor progressive Justice Party. (Yonhap)