Rep. Lee Jae-myung, front row center, leader of the main opposition Democratic Party of Korea (DPK), chants a slogan during a rally near Seoul Station, Saturday, with party members and supporters carrying signs that read "Conduct special investigation into (first lady) Kim Keon Hee." Yonhap

Opposition parties have been intensifying their protest against President Yoon Suk Yeol and first lady Kim Keon Hee amid a swirling election meddling scandal surrounding the presidential couple and a political broker.

Their upgraded offensive, which even includes calls for Yoon's impeachment, came as the president's job approval rating plummeted to the lowest level since his inauguration in May 2022, at 19 percent.

The ruling party, however, is struggling to counter the offensive as new allegations involving the first couple — particularly Kim — continue to surface. The presidential office is reiterating its position that the first couple does not bear any legal responsibility even if the allegations are proven true, which falls short of public expectations for higher moral standards.

On Saturday, the main opposition Democratic Party of Korea (DPK) held a large rally in central Seoul, demanding a special counsel bill to investigate allegations against Kim, including stock manipulation, her receipt of a luxury bag and interference in the party's candidate nominations for the 2022 parliamentary by-elections and the April 2024 general elections.

According to the DPK, approximately 300,000 people participated in the rally near Seoul Station, carrying signs that read "Conduct a special investigation into Kim Keon Hee." Some DPK lawmakers also called on Yoon to "step down."

"State affairs are dominated by unelected and unaccountable people, not the president. The Yoon administration is habitually breaking laws. We demand the president and the government immediately accept the bill mandating a special counsel investigation into Kim. A sincere reflection and apology to the public is the starting point for change," Rep. Lee Jae-myung, leader of the DPK, said at the rally.

These calls came amid snowballing allegations surrounding the presidential couple and Myung, a self-proclaimed political consultant.

Myung claimed that the first couple, particularly Kim, sought his advice on various political issues, revealing text messages he exchanged with her.

But his claims are now heavily impacting Yoon following the DPK's release of a recorded phone conversation between the president and Myung. The conversation suggests that Yoon used his influence to assist Kim Young-sun, a former lawmaker from the ruling People Power Party (PPP), in winning the nomination for a district in South Gyeongsang Province ahead of the 2022 by-elections. Allegedly, Myung leveraged his personal connections with the presidential couple to secure Kim's nomination.

Rep. Park Chan-dae, the floor leader of the DPK, cautioned that the party will unveil more information about the informal adviser allegedly exerting influence in state affairs. "We will proceed with voting on Nov. 14 for a new bill calling for a special counsel investigation into the allegations involving Kim. Yoon should clarify his phone call with Myung," Park told reporters on Sunday.

The DPK and other opposition parties had previously pursued two bills for a special counsel investigation into Kim, both of which were abandoned following failed votes in the Assembly. They have now proposed a third bill.

The new bill includes recent allegations that Kim solicited help from Myung to manipulate public opinion polls and exercise undue influence over the ruling party's candidate nominations for the 2022 by-elections and April's general elections.

The scandal has caused Yoon's approval rating to drop below 20 percent for the first time, standing at 19 percent, the lowest level since he took office in 2022, according to Gallup Korea's weekly poll released on Friday. Additionally, 72 percent of respondents disapproved of Yoon's performance, marking an all-time high.

The pollster surveyed 1,005 respondents from Tuesday to Thursday and the results indicated that issues surrounding Yoon's embattled wife were among the reasons behind their disapproval of the president.

Rep. Choo Kyung-ho, floor leader of the ruling People Power Party, speaks during a press conference at the National Assembly in Seoul, Sunday. Yonhap

Rep. Choo Kyung-ho, floor leader of the PPP, said the party and the government take Yoon's all-time low approval rating seriously.

"The party takes this matter very seriously. I believe the president is also aware of the gravity of the situation and is looking for ways to address public concerns," Choo said during a press conference at the Assembly, Sunday.

While the PPP criticizes the DPK's offensive against the presidential couple and the repeated proposals for a special probe bill targeting Kim, the ruling party lacks effective defensive measures as new allegations continue to emerge daily.

PPP leader Han Dong-hoon's earlier request for the president to address the first lady issues has not been met.

The presidential office, for its part, denies that Yoon interfered in the candidate nominations, with presidential chief of staff Chung Jin-seok commenting on Yoon's phone conversation with Myung, stating, "The conversation is not an issue politically, legally, or from a common sense perspective."

Choo also hinted that Yoon is unlikely to deliver a 2025 budget speech at the Assembly on Monday. "The prime minister will likely present the budget proposal on Yoon's behalf. Given the situation that the DPK is taking to the streets to impeach the president, Yoon's appearance at the parliament will only create a scene of political strife," Choo said. If Yoon skips the budget speech, this would mark the first time in 11 years that an incumbent president has not directly addressed the Assembly on the budget.

Meanwhile, Kim Young-sun appeared before prosecutors on Sunday for questioning over allegations of providing 96.7 million won ($70,000) to Myung on several occasions between August 2022 and February this year, in return for his help to get the candidate nomination. Prosecutors are expected to summon Myung sometime this week.