The tide of the presidential race in South Korea has shifted again, poll results showed Monday, this time again in favor of presidential nominee Yoon Suk-yeol of the main opposition People Power Party.

Successful campaign efforts from Yoon’s side following the end of a damaging internal feud, as well as the abrupt death of a whistleblower in a case involving main rival Lee Jae-myung of the ruling Democratic Party of Korea, are believed to have aided Yoon in garnering more support in the last week.

A Realmeter poll of 3,031 voters commissioned by OhmyNews that ran from Jan. 9 to Friday showed Yoon leading with 40.6 percent support, up 6.5 percentage points from a week earlier. He is followed by Lee Jae-myung of the ruling Democratic Party at 36.7 percent, down 3.4 percent points on-week.

Yoon was leading the race with 3.9 percentage points distance from Lee, which is outside the margin of error at plus or minus 1.8 percentage points with a 95 percent confidence level for the latest survey.

The sudden change in voter support is largely credited to Yoon’s efforts to appeal to young male voters with campaign promises like abolishing the Ministry of Gender Equality and Family and providing 2 million won ($1,680) a month in wages for conscripted service members.

He has also stayed in line with the conservative bloc’s hard-line stance on North Korea, emphasizing the need for a “preemptive strike” last week after North Korea conducted its second missile test of the year.

In the meantime, support ratings for his rival Lee likely suffered from the death of a lawyer who is known as the first person to have provided a civic group with information on Lee’s alleged payment of legal fees by proxy in 2018.

Since Lee announced his bid for the presidency last year, three officials related to allegations involving Lee have been found dead. The ruling party has denied all allegations, but voters are likely to have questioned Lee’s moral aptness upon the lawyer’s death and following accusations from political circles.

The same Realmeter survey found Ahn Cheol-soo of the minor opposition People’s Party at 12.9 percent support, up 1.8 percentage points from last week. Rep. Sim Sang-jung of the minor left-wing Justice Party dropped 0.8 percentage point to 2 percent.

Ahn’s ratings have gotten a boost as voters increasingly disfavored Yoon after the People Power Party found itself embroiled in an internal feud and accusations were leveled against Yoon’s wife Kim Keon-hee.

The change in public opinion drew discussions of Yoon and Ahn merging candidacies before the election date, although Ahn has repeatedly denied any intention to unify his candidacy with another candidate.

For the latest survey, in a hypothetical scenario where Yoon and Ahn merged candidacies to have Yoon run as the unified candidate, Yoon stayed at the top of the poll with 45.2 percent support, followed by Lee at 37 percent and Sim at 3.8 percent.

If Ahn was the unified candidate in such a scenario, 42.2 percent indicated support for Ahn, with Lee at 34.3 percent and Sim at 3.8 percent.

For more information regarding the survey results, visit the National Election Survey Deliberation Commission homepage.