SEOUL, May 11, 2025 (BSS/AFP) - South Korea's People Power Party registered former labour minister Kim Moon-soo as its official presidential candidate on Sunday, a day after it attempted to cancel his candidacy.

The ruling People Power Party (PPP) has been in turmoil since former president Yoon Suk Yeol was ousted after he declared martial law in December.

Last week, Kim won the PPP's primary to run as its candidate in presidential elections on June 3.

But before dawn on Saturday, his nomination was cancelled and the party moved to replace him with ex-prime minister Han Duck-soo, who had resigned to contest the race initially as an independent.

The attempt however failed when party members voted down a motion to switch the presidential candidate from Kim to Han -- automatically reinstating Kim as the nominee.

"Today, I have completed the registration process for the presidential candidacy. I would like to express my gratitude to all the citizens who have shown concern and to my fellow party members," Kim told reporters after he registered his candidacy at the National Election Commission.

"This presidential election is particularly crucial as it will determine who can overcome the current crisis facing our nation and work toward the happiness of our people," said the 73-year-old.

"I pledge to do my utmost to secure victory and lead South Korea toward becoming an even greater nation," he added.

Kim added that he is scheduled to meet Han at the party headquarters soon after, and emphasised that he will do his best to leverage Han's "remarkable capabilities".

Separately, Han held a press conference, announcing he will step down.

"I accept everything with humility and respect the outcome. I sincerely wish candidate Kim Moon-soo of the People Power Party and his supporters success in this election," said Han.

"Now, I am stepping back from everything and returning to the life of an ordinary citizen."

The deadline to register candidates with the National Election Commission closes later on Sunday.

Analysts say the country's right needs to rally around a single candidate to avoid an opposition landslide at the election, with Lee Jae-myung of the Democratic Party leading in polls.

A National Barometer Survey released this week showed Lee -- who currently faces multiple criminal trials -- leading Kim 43 percent to 29 percent.