President Yoon Suk Yeol (right) shakes hands with Han Dong-hoon, leader of the ruling People Power Party, at Seoul Air Base in Seongnam, south of Seoul, in this file photo taken Oct. 11, upon Yoon's return from his three-nation Southeast Asia trip. (Yonhap)

President Yoon Suk Yeol and the ruling party chief were set to meet Monday to discuss a range of pressing issues, likely including controversies involving first lady Kim Keon Hee.

Yoon and Han Dong-hoon, chair of the People Power Party, were scheduled to meet for tea at the presidential office at 4:30 p.m., with the presidential chief of staff, Chung Jin-suk, also attending, Yoon's office said.

The meeting comes as Yoon and the ruling party seek to recover from declining approval ratings, with Yoon now at the midpoint of his five-year term.

Yoon's decision to meet with Han comes amid the growing sense of a crisis within the ruling party as the main opposition Democratic Party has been stepping up a political offensive against Yoon. Some DP lawmakers have raised the possibility of impeaching Yoon over allegations surrounding the first lady.

The PPP won two out of the four seats up for grabs in last week's by-elections, delivering what was considered a show of public confidence in Han's leadership highlighted by his commitment to getting to the bottom of controversies surrounding the first lady.

Following the election results, Han has reiterated his call for a reshuffle in the presidential office to sideline those in the first lady's "line," who are allegedly exercising undue influence on state affairs.

The first lady has been accused of involvement in a stock manipulation scheme, an illegal receipt of a luxury bag and interference in the PPP's candidate nominations ahead of the April general elections.

Last week, the prosecution decided not to indict Kim over her alleged involvement in a stock manipulation scheme involving Deutsch Motors Inc. between 2009 and 2012.

The DP strongly protested the decision and introduced a bill calling for a special counsel probe into allegations involving Kim. It marked the third time the party has submitted such a proposal, following two previous attempts that were nullified by Yoon's vetoes. (Yonhap)