ⓒYONHAP News

Presidential candidate Ahn Cheol-soo of the minor People's Party dropped out of the race and endorsed Yoon Suk Yeol of the main opposition People Power Party(PPP) on Thursday, a day before early voting started.

The surprise announcement came four days after Yoon said Ahn had notified him of a collapse in negotiations to field a single candidate.

With the agreement, the election on Wednesday will be a three-way race, including the ruling Democratic Party's Lee Jae-myung and Sim Sang-jung of the minor opposition Justice Party.

In a joint press conference at the National Assembly on Thursday, Yoon and Ahn said they agreed to unite their candidacies to achieve a transfer of power, adding that they have no doubt that their decision will ensure a victory for the opposition bloc.

They said they will prepare to change and reform the country in accordance with the wishes of the public. Yoon and Ahn said that they are now one team and will compensate for each other’s weaknesses to secure a victory in the election and form a successful administration.

In a statement, the two sides said they will consult with each other on forming the presidential transition team and a joint government. They also agreed to pursue a merger of their parties right after the election.

Democratic Party(DP) candidate Lee said he will not stray from the path toward a stronger economy, peace and unity, in response to the news of two opposition rivals agreeing to field a single candidate.

Speaking to reporters on Thursday, Lee said he has faith in history and the public. His comment came after minor Ahn dropped out of the race and endorsed Yoon.

When asked whether he had made contact with Ahn prior to Thursday’s announcement, the DP candidate declined to comment.

Earlier, Rep. Woo Sang-ho, the chief of the DP campaign committee, said the merger was tantamount to "collusion," adding that the move will face public backlash. He said the committee will transition to a 24-hour emergency mode to respond in full force. 

At a press conference on Thursday, Justice Party presidential candidate Sim claimed that by withdrawing from the race and partnering with the PPP, Ahn was conceding to the two main political parties.

She expressed disappointment and regret that she and Ahn can no longer compete and cooperate to achieve a political transition overcoming a political duopoly by the two major parties.

Emphasizing that the move has stranded herself and the people who desire political change, in fighting against the monopoly of the major parties, the minor party candidate asked for support from voters who are seeking a multiparty system.

Reflecting on the agreement between Yoon and Ahn to join forces, Sim forecast the unity to offer a complex set of variables ahead of the election.