Up to half-a-million people are expected to take to the streets of Seoul today to demand the resignation of embattled President Park Geun-Hye.

Authorities say 25-thousand police officers are standing by for the expected crowd of around 170-thousand. Organizers say they expect more than 500-thousand demonstrators. Either number would make it one of the biggest anti-government rallies since the pro-democracy protests of the 1980s.

Park has issued several apologies, reshuffled her top officials, and even agreed to relinquish some of her extensive executive powers. But calls for her to step down have been relentless.