Former prime minister and presidential hopeful of the ruling party Rep. Lee Nak-yon said on Thursday it doesn’t make sense that former Prosecutor General Yoon Seok-youl is running for president given what he said earlier about his convicted mother-in-law.

“When he was in the prosecution, (the prosecution) did not indict his mother-in-law, and he told Parliament that he will obviously have to step down as prosecutor general if she is guilty,” Lee said in a radio interview Thursday morning.

“If he has to quit prosecutor general should she be guilty, is it right that he runs for president when she is guilty?”

Yoon’s mother-in-law, surnamed Choi, was sentenced to three years in prison last week for setting up a medical foundation with three business partners to open a nursing hospital in 2013 despite having no medical qualifications, and fraudulently collecting 2.29 billion won in state benefits to run the hospital until 2015.

Choi was immediately taken into custody.

“(Yoon’s) mother-in-law is jailed; wife is under investigation; and Yoon himself has been accused (of power abuse among others). It is unacceptable in my opinion that he’s running for president despite all that,” Lee said.

In response to the radio host’s comment that Yoon is acting like his mother-in-law’s imprisonment wouldn’t be a problem, Lee said, “would the court have jailed (her) if there were no problems? I’m suspicious if he really has upheld the rule of law throughout his lifetime.”

When asked if rumors about Yoon’s wife’s past and the validity of her university thesis should be verified, Lee said they should be.

“I don’t want to speak about (the rumors) … They must be verified. As for the thesis, it’s already being reported that Kookmin University is looking into it, and it makes you cringe just even speaking about it,” Lee said.

About Gyeonggi Province Gov. Lee Jae-myung, currently the ruling Democratic Party’s front-runner in the presidential preference polls, the former prime minister said he was “rather rough around the edges,” making reference to the governor’s recent comment asking whether he should pull down his pants during a televised debate and calling legislators “drug peddlers.” The comments were inappropriate given that the president is “the face of the nation,” Lee said.

Lee Jae-myung made the pants remark in response to a question over a previous scandal with an actress.

Regarding concerns that Democratic Party leader Song Young-gil was taking sides with the governor, Lee said it is highly undesirable that such concerns are growing, and cautioned Song to give it more thought.

The journalist-turned-politician also denied reports that he and Chung Sye-kyun, another former prime minister running for the ruling party’s nomination as presidential candidate, spoke about unifying their candidacies.

“It was never mentioned (during their recent meeting). There are various ways to cooperate,” he said.

Separately, Lee disagreed with opposition politicians’ pledges to scrap the Ministry of Gender Equality and Family, saying the ministry still has work to do, which is to realize a society where both genders are equally treated.