The overwhelming majority of candidates from the two main parties picked to run in the upcoming legislative election so far are viewed as part of the parties’ respective mainstream factions, data showed Sunday.

The outcome contradicts earlier pledges made by the two parties to select more candidates from their respective nonmainstream pools for the April 10 general election in order to promote fairness.

According to data provided by the ruling party, the majority of the candidates from the ruling People Power Party tapped to run and compete in some 200 of the total 254 districts across the country, as of Sunday, are viewed to be “pro-Yoon Suk Yeol.”

While many in the ruling party’s nonmainstream faction failed to land the party's nomination, practically everyone in the party considered to be part of the pro-Yoon faction made the cut.

The only pro-Yoon lawmaker left out is three-term lawmaker and People Power Party Rep. Chang Je-won, who in December last year declared that he would not run again of his own volition. Chang, viewed as one of Yoon's closest confidants, took the bold step in the hope that his decision “might help the Yoon Suk Yeol government to succeed through a victory in the general elections.”

Among those who failed to make the cut is former chair of the People Power Party's Nowon-gu, Seoul chapter Jang Il, who set himself on fire in front of the ruling party headquarters in western Seoul on Saturday to protest the party leadership’s decision not to nominate him. Police extinguished the flames as his clothes caught fire, and he was subdued and transported to the hospital. Police report that he sustained no serious injuries.

On criticisms that the majority of the candidates are of the pro-Yoon faction, People Power Party interim Chair Han Dong-hoon said "any attempts to derogate our own candidates won't help" in a text message sent to party members on Friday.

Han's message came after the former head of the People Power Party's Vision Strategy Office and a recently confirmed candidate for Songpa-gu, Seoul, Kim Geun-sik, implied in a Friday radio interview that more pro-Yoon faction members should have been cut from the candidate list to "move voters' hearts" in terms of intraparty reform.

The main opposition Democratic Party of Korea has also tapped an overwhelming majority of its candidates from close aides or supporters of Chair Lee Jae-myung to compete in 170 of the total 254 districts in the election so far.

However, the main opposition party's election nomination process has been marred by a series of announcements by nonmainstream politicians -- a number of whom decided to leave the party officially -- criticizing it.

On Wednesday, five-term lawmaker Sul Hoon announced he would leave the Democratic Party after being placed in the bottom 10th percentile in the party leadership's performance review for legislative activity. The leadership has claimed they made fair decisions in candidate nominations based on the performance review.

Im Jong-seok, a former presidential chief of staff under the previous Moon Jae-in administration, also hinted that he might leave the party after the leadership recently snubbed him from running on his home turf of the Jung-Seongdong constituency in Seoul.

Four-term lawmaker and Deputy National Assembly Speaker Rep. Kim Young-joo, Rep. Lee Su-jin and Rep. Park Young-soon were among others who recently left the party.