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.  

Regarding concerns that joining the PPP could estrange some supporters, Yoon said entering the party was inevitable to achieve a change of administration.