ⓒYONHAP News

Former Prosecutor-General Yoon Seok-youl joined the main opposition People Power Party(PPP) on Friday, a month after declaring his presidential bid on June 29.

After handing over the related paperwork to Rep. Kwon Young-se at party headquarters in Yeouido, Seoul, Yoon said that in order to attain a transition of power, joining the main opposition party to fairly compete in its primaries was the right thing to do.

The leading opposition presidential contender said he believes he will attract broader voter support by joining the party.

He said he previously wanted more time to hear the views of the public away from the party, but after meeting many people, he decided it would be better to eliminate uncertainty.  

Shortly before Yoon joined the PPP, the eleven other presidential contenders of the main opposition gathered for the first time to learn the rules of the party’s primary. 

Among the participants were former Board of Audit and Inspection head Choe Jae-hyeong, former lawmaker Yoo Seong-min and former Incheon Mayor Ahn Sang-soo. 

The participants vowed to focus on policies rather than slander and defamation, and expressed concerns over campaign strategies, factional politics and the way the race will be carried out.

Former legislator Yoo Seong-min said the party won’t be able to win the presidential race solely by focusing on denouncing the current government while Rep. Kim Tae-ho said party members must refrain from constantly changing their factions to favor a particular candidate.

The former Incheon mayor, for his part, expressed opposition to the party’s plan to survey the public instead of party members in the first round of the primary.

In the ruling Democratic Party(DP) the party's leadership and election officials brokered a tentative gentlemen's agreement between the six presidential contenders as competition threatened to grow ugly.

The DP's primary candidates on Wednesday attended a so-called "one-team" accord signing ceremony and agreed to refrain from slanderous campaigns and encourage fair competition.

The six challengers swore an oath to present future-oriented policies, pursue dignity and honesty, compete in good faith and abide by party platforms and election rules.

Speaking to reporters afterwards, the candidates said the party should sanction malicious propaganda and that it should differentiate between vetting one's credentials and running a negative campaign. 

However, Gyeonggi Province Gov. Lee Jae-myung and former DP chairman Lee Nak-yon clashed again during the first televised debate held the same day.

Recent opinion polls showed Lee Nak-yon catching up to presidential frontrunners, Gov. Lee and former top prosecutor Yoon Seok-youl, who is a potential opposition candidate.