Former Prosecutor General Yoon Seok-youl, now a presidential contender, said his heart aches when he thinks about ex-Presidents Park Geun-hye and Lee Myung-bak, who were jailed for corruption as a result of investigations that he led.

“No matter the reasons, (I) offer consolation and express regrets to all who have gone through pain because of me,” Yoon said in an interview with the Dong-A Ilbo published Monday, about the political corruption probes that he led as chief of the Seoul Central District Prosecutors’ Office in the beginning of the Moon Jae-in administration.

“It’s not just about the investigations in the early days of the administration. A prosecutor should be considerate of those going through hardship due to the probe and always feel sorry. I fully understand that (they) can have ill feelings or even rancor against me.”

About the possibility of granting amnesty to the two former presidents, he said the reason a president has that right is to bring the Korean people together.

“I think President Moon will make a decision if he believes it is necessary to bring Koreans together,” said Yoon, who registered as a preliminary presidential candidate with the nation’s election committee on Monday.

About the possibility of unifying his candidacy with that of Choe Jae-hyeong, former chairman of the Board of Audit and Inspection, Yoon said he “will make any decision, including unifying candidacy, if it will make the change of government certain.”

When asked if he was considering joining forces with Choe before or after joining the main opposition People Power Party, Yoon said, “Whatever it is, this administration has to be replaced. Everyone who wants a change of government should join forces. I can say for sure that I won’t disappoint the people who want government change.”

He gave the same response when asked whether he would join the People Power Party.

“Because the country must move on common sense, I plan to decide based on the criteria of whether it can make the change of government happen for sure,” the ex-chief prosecutor said.

About various suspicions surrounding his family, Yoon said, “If it’s slander for slander without any grounds, the people will make their judgments even if I don’t explain.”

With Yoon yet to decide whether to join the main opposition party and Choe yet to make his presidential bid official, ex-Finance Minister Kim Dong-yeon is another opposition presidential hopeful talked about outside the People Power Party.

In the opposition camp, over a dozen people have declared or plan to declare presidential bids. Former four-term lawmaker Yoo Seung-min, Jeju Gov. Won Hee-ryong, Rep. Hong Joon-pyo, Rep. Ha Tae-keung, and Rep. Yoon Hee-sook are among them.

The ruling Democratic Party narrowed down its lineup of presidential contenders to six at the first round of the party primary on Sunday.

They are Gyeonggi Gov. Lee Jae-myung, ex-party chief Lee Nak-yon, ex-Prime Minister Chung Sye-kyun, ex-Justice Minister Choo Mi-ae, Rep. Park Yong-jin and Rep. Kim Du-kwan.

In the latest presidential preference poll, Yoon and Gov. Lee remained in the lead while support for Lee Nak-yon, who officially announced his presidential bid a week ago, jumped 5.9 percentage points from a week ago to 18.1 percent.

In the nationwide poll of 1,014 people conducted last Friday and Saturday by the Korea Society Opinion Institute, commissioned by TBS, Yoon was ahead with 29.9 percent, followed by Gov. Lee (26.9 percent), ex-Democratic Party chief Lee (18.1 percent), former People Power Party legislator Yoo (4.5 percent), ex-Justice Minister Choo (4.2 percent), Rep. Hong Joon-pyo of the People Power Party (4.1 percent), and former Board of Audit and Inspection chief Choe (2.5 percent).