ANKARA

South Korea's ruling party is struggling to field a joint candidate for the upcoming snap presidential election as its nominee refuses to unify his candidacy with former Prime Minister Han Duck-soo, Seoul-based Yonhap News reported on Thursday.

People Power Party presidential candidate Kim Moon-soo has called on party leadership to stop pressuring him to unify his campaign with Han in a bid to consolidate conservative support against Democratic Party front-runner Lee Jae-myung, who currently leads in opinion polls ahead of the June 3 election.

Kim’s remarks came a day after he and Han failed to reach an agreement on running as a single candidate. A survey published Tuesday by the JoongAng Ilbo daily showed Lee holding nearly 50% support.

"I demand that the party leadership stop trying to bring me, a legitimate candidate, down," Kim told reporters.

"I will not yield to any injustice."

Kim was nominated by the People Power Party as its presidential candidate earlier this month, whereas Han, who had served as an acting president, announced his presidential bid last week.

Despite leading Kim in recent opinion polls, Han has said he will not formally enter the race unless a deal is reached to unify the conservative ticket.

With just four days remaining before the official candidate registration deadline, both candidates have been under pressure to present a united front against the Democratic Party’s Lee.

*Writing by Aamir Latif