The ruling party interim nominee, former Justice Minister Han Dong-hoon faces an uphill battle as he seeks to lead party reform while tackling opposition proposals for a special investigation into first lady Kim Keon Hee.

Han will be elected as the chair of the emergency committee of the ruling People Power Party on Tuesday, following the approval of the party's national committee. An emergency committee led by Han will be launched on Friday.

But even prior to the official launch, Han will have to deal with waves of changes brought on by the planned departure of former party leader Lee Jun-seok scheduled for Wednesday.

Lee, who has been estranged from the ruling party leadership after refusing to cooperate with President Yoon Suk Yeol's aides, announced his decision to establish a new political party earlier this year.

Some within the ruling party have been calling for Han to convince Lee to remain in the party, or at least bring him onside, fearing the loss of appeal to male voters in their 20s and 30s that Lee brings. Lee is a rare member of the conservative bloc to have overwhelming support from young male voters.

"I hope Han will meet with Lee Jun-seok and former lawmaker Yoo Seong-min in the process of forming the emergency leadership committee. It's important to convince as many as we can to stay on our side," three-term lawmaker and ruling party Rep. Ha Tae-keung said in a recent KBS radio interview.

However, Han has so far remained tight-lipped about the matter, while Lee has expressed his determination to launch a party of his own.

Meanwhile, Han is expected to deal with the aftermath of the main opposition Democratic Party's plans to unilaterally pass two investigation proposals, including the one into allegations of illegal stock trading by first lady Kim Keon Hee, during a National Assembly plenary meeting on Thursday.

The main opposition lawmakers can pass them on their own as they hold a controlling majority in the Assembly. The ruling People Power Party and the presidential office have opposed the bills.

Yoon is expected to veto the proposals.

The presidential office condemned the opposition party's move Sunday, with Lee Kwan-sup, director of national policy at the presidential office, calling it an attempt to leave a "scratch" on the Yoon administration ahead of the elections, in a TV interview.

Overall, Han is expected to prioritize picking the members of the emergency leadership committee upon assuming the new role. The current ruling party floor leader Yun Jae-ok is currently a strong candidate for a committee member.

Last week, Han was appointed by the ruling party to take on the role of its interim leader ahead of the general election scheduled for April next year.

Han's upcoming role is projected to fill the leadership void left by former party chairman Kim Gi-hyeon's decision to resign last week. Kim stepped down in a surprise move, which was widely seen as an effort to support party reform.

Several ruling party heavyweights had since mentioned that the 50-year-old was a strong candidate to head the party's emergency leadership committee.

Han, viewed as Yoon's right-hand man after working closely beside him for nearly a decade as both a prosecutor and a Cabinet member.