Four candidates in the main opposition People Power Party’s(PPP) primary for April's Seoul mayoral by-election will participate in their first live debates broadcast on the party's official YouTube channel Tuesday afternoon.

Former floor leader Na Kyung-won will face off against former lawmaker Oh Shin-hwan, while former Seoul Mayor Oh Se-hoon will go up against Seoul's Seocho district chief Cho Eun-hee.

There will be no dress code or prepared documents in the standing one-on-one debates, and a panel of one-thousand citizens will evaluate each candidate afterwards.

After two more rounds set for Friday and next Tuesday, the four candidates will take part in a group debate on February 26, before the final candidate is announced on March 4 following a public poll.