SEOUL, South Korea (AP) — South Korea's opposition politicians on Wednesday called for nullifying a settlement reached between Seoul and Tokyo on compensation for South Korean women forced into sexual slavery by Japan's military in World War II.

Their statements on the anniversary of the deal came amid growing efforts to erase some of the key policies of impeached President Park Geun-hye. Facing political and public pressure, the Education Ministry on Tuesday backtracked from a much-criticized plan to require middle and high schools to use only state-issued history textbooks from next year.

Woo Sang-ho, floor leader of the main opposition Democratic Party, said the party will work to invalidate the sex slave agreement if it wins the presidential elections that could take place in just months, echoing similar promises made by the party's potential candidates.

Kim Gyeong-rok, spokesman of the People's Party, criticized the Park administration for "selling away" the victims' honor and dignity, and said the issue couldn't be resolved without Japan offering a sincere apology and admitting legal responsibility.

Under the agreement, Japan pledged to give 1 billion yen ($8.5 million) to a foundation to help support the former sex slaves. South Korea, in exchange, vowed to refrain from criticizing Japan over the issue. The deal was widely criticized in South Korea, where many thought the government settled for far too less.

Hundreds of protesters gathered around a statute of a girl symbolizing South Korean sexual slavery victims near a street in Seoul where Japan has been reconstructing its embassy building, calling for the agreement to be scrapped and the foundation to be dissolved.

It's unclear whether South Korea could reverse an agreement both governments described as "irreversible." Park's conservative ruling party criticized Woo, accusing him of attacking the deal without proposing alternatives and acting like his party already won the presidential race.

Park, who was impeached by the country's opposition-controlled parliament over a corruption scandal on Dec. 9, had endorsed the state history textbooks, saying it would inspire patriotism in students. Her critics saw the books at an attempt to whitewash the brutal dictatorships that preceded the country's bloody transition toward democracy in the 1980s.

Park is the daughter of slain military dictator Park Chung-hee, whose legacy as a successful economic strategist is marred by records of violent civilian oppression.

Education Minister Lee Joon-sik said schools could keep using history textbooks made by private publishers next year, although they can also choose to use state textbooks on a trial basis.

South Korea's Constitutional Court has up to six months to decide whether Park should permanently step down or be reinstated. If she is formally removed from office, a presidential election must be held within 60 days.