Key Points

The June 3 presidential vote is being held to pick a successor to Yoon, who was ousted over his failed martial law bid, and the PPP has remained divided about Yoon's ouster.

Asked about Yoon's possible expulsion from the party, PPP presidential candidate Kim Moon-soo told reporters, "I believe former President Yoon will make his own decision. It is right to respect his judgment."

The remarks by Kim contrasted with his comment Tuesday, when he said he was not considering expelling Yoon from the PPP, Yonhap news agency reported.

Some PPP lawmakers also said a voluntary exit by Yoon from the party would help Kim woo centrist voters.

"I hope Yoon remains silent at least while undergoing trials, and that he voluntarily leaves the party," Yang Hyang-ja, a co-chair of the PPP's election committee, told KBS radio, saying "compulsory measures" could follow if he does not.

Han Dong-hoon, a former PPP leader who trailed Kim in the primary, reiterated his calls for the party to expel Yoon to overcome his martial law debacle.

In response, Kim Yong-tae, the party's interim leader nominee, said he will clarify the PPP's stance on its relationship with Yoon once officially appointed on Thursday.

Earlier in the day, South Korean Democratic Party (DP) presidential candidate Lee Jae-myung called on the PPP to immediately expel former President Yoon Suk Yeol from the party, criticising him as a "military coup leader."

Lee's call came a day after the PPP's candidate Kim Moon-soo said he was not considering expelling Yoon, who was ousted over his short-lived martial law imposition in December and now faces criminal charges of leading an insurrection.

"The People Power Party must immediately expel military coup leader Yoon Suk Yeol now," Lee said during a campaign rally in Busan, about 320 kilometres southeast of Seoul.

- IANS