South Korea's ruling People Power Party chose its official presidential candidate, former labor minister Kim Moon-soo, on Sunday after attempting to cancel his candidacy.

Kim won the party's primary last week to run as the candidate in the elections set for June 3.

However, the party attempted to cancel his candidacy and replace him with former Prime Minister Han Duck-soo.

The party leadership believed Han had a better chance than Kim to win the elections.

In an unprecedented move, they tried to reinstate Han as the candidate. Kim denounced this as an "overnight political coup."

PPP members voted against a motion to switch the presidential candidate from Kim to Han, thus reinstating Kim as the candidate.

A party spokesperson said the vote passed by a narrow margin.

Kim thanks supporters

"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. I pledge to do my utmost to secure victory and lead South Korea toward becoming an even greater nation," Kim, 73, told the media after registering his candidacy at the National Election Commission.

He thanked his supporters and members of the party.

Han said he accepted the outcome of the vote and congratulated Kim.

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

Kim was a labor activist before joining the conservative party in the 1990s.

The two are set to meet at the party headquarters.

Turmoil after ouster of former President Yoon Suk Yeol

The PPP has been in a state of turmoil since the impeachment of former President Yoon Suk Yeol last December, after he attempted to impose martial law.

Han served as the acting president since then and resigned on May 2 to pursue his presidential candidacy.

The opposition Democratic Party's candidate, Lee Jae-myung, who faces several criminal trials, is currently leading in the polls.

Edited by: Louis Oelofse