As the chorus grows louder for South Korean President Park Geun-hye to resign over a corruption scandal, a power vacuum is weighing on her administration, leaving her political survival in doubt and the vulnerable economy exposed to political shocks.

South Korean opposition political parties said this week they will review strategies to impeach Park after prosecutors said she was an accomplice in the corruption scandal.

Park's close friend and a former presidential aide were indicted on Sunday for abuse of power for pressuring big businesses to contribute funds to foundations at the center of the scandal.