The seven defense lawyers of ousted President Park Geun-hye resigned en masse Monday to protest what they say is a biased corruption trial.

Speaking for the first time since the start of her trial, Park, who was removed from office and arrested in March, called the proceedings against her an act of "political revenge."

Park was impeached in December by parliament and in March fired by the country's top court, following revelations of her involvement in a massive corruption scandal centered on a friend of 40 years and some of the country's top businessmen, including Samsung heir Lee Jae-yong.

She faces charges of bribery, extortion, abuse of power and other high-profile corruption charges that could potentially send her to jail for life.

