Moon Jae-in, the current frontrunner in the race for the presidency, will this week register his candidacy for his party's primaries, an aide said Sunday.

Moon, a former leader of the main opposition Democratic Party, will sign up for the primaries through his spokesman Rep. Kim Kyung-soo at 11 a.m. Monday, the aide said on the condition of anonymity. A formal declaration of his presidential bid will come later once the fate of impeached President Park Geun-hye becomes clearer, he added.

The Constitutional Court has been reviewing the legitimacy of Park's impeachment over an influence-peddling scandal centered on her and her friend Choi Soon-sil.

Should the court remove her from office, South Korea is required to hold a presidential by-election within 60 days. If Park is reinstated, the election will be held in December as scheduled.

According to a poll by Gallup Korea last week, 29 percent of those surveyed favored Moon as the next president. (Yonhap)