BOSTON (AP) — A group that opposes affirmative action urged a federal appeals court Tuesday to overturn a ruling that cleared Harvard University of discriminating against Asian American applicants.

Students for Fair Admissions has accused the Ivy League college of deliberating holding down the number of Asian Americans accepted in order to preserve a racial balance on campus.

But U.S. District Judge Allison D. Burroughs ruled in October that Harvard’s admissions process, while “not perfect,” passes constitutional muster and that there is “no evidence of any racial animus whatsoever.”

Lawyers for Students for Fair Admissions said in a brief filed with the 1st U.S. Circuit Court of Appeals on Tuesday that Harvard “imposes a racial penalty on Asian-American applicants” and that the school’s “transparent regime of racial balancing flagrantly violates settled law.”

“It is quite unusual for a civil-rights defendant to confess. Yet Harvard admits that its goal is to ensure racial balance, and that it has engineered the admissions process to achieve that illegal pursuit,” lawyers for the group told the appellate court.

The group has said it will appeal all the way to the U.S. Supreme Court if necessary.

Harvard has denied any discrimination and and said race is considered only in the narrow way that has been upheld in earlier Supreme Court cases. The school said in an emailed statement Tuesday that it will “vigorously defend” the lower court’s decision.

“Today’s filing by Students for Fair Admissions further exposes their ultimate goal of removing the consideration of race in college and university admissions,” Harvard said.