Besides South Korean President Park Geun-hye, the biggest casualty of the country's mushrooming political corruption scandal may be the presidential aspirations of United Nations Secretary-General Ban Ki-moon.

Although he has not declared his candidacy, Ban was until a month ago the front-runner in opinion polls to win the election scheduled for Dec. 20, 2017, a race he was widely expected to contest from Park's conservative Saenuri Party.

But the scandal that has become known as "Park Geun-hye-Gate" and threatens Park's presidency has sowed division in the party. An impeachment vote is set for later this week, and Ban's standing in polls has declined, while the Saenuri has become a much less viable platform for a run.