As lawmakers seek to expand a 20-year-old school voucher program, advocates are crying foul, saying the program discriminates against students with disabilities.

In a complaint filed with the U.S. Department of Justice this week, officials at the American Civil Liberties Union and Disability Rights Wisconsin as well as two parents of children with disabilities claim that private schools participating in a Milwaukee school voucher program are not accepting students with disabilities.

The voucher program provides public funds for low-income Milwaukee students to attend private schools in the area. However, the complaint naming the state of Wisconsin, the state Department of Public Instruction and two private schools alleges that in practice most students with disabilities are not given the option to enroll and are instead restricted to public schools in violation of the Americans with Disabilities Act.

“There is essentially one option for students with disabilities: (Milwaukee Public Schools). Students without disabilities have a publicly-funded ‘choice:’ they can attend private schools with a publicly-funded voucher or choose to stay in public schools,” the complaint indicates.

Currently just 1.6 percent of students attending private schools that accept vouchers have disabilities, while 19.5 percent of Milwaukee Public Schools students are in special education, according to the civil rights complaint.

The legal action comes as Wisconsin lawmakers are considering an expansion of the voucher program. A legislative committee recently voted to loosen the program’s income requirements and allow students in other cities outside of Milwaukee to participate.

Those behind the complaint want the Justice Department to investigate the voucher program and prevent any expansion until discrimination issues are addressed.

“Increasing the size of the voucher program — as the state intends to do — will only lead to even more discrimination and more segregation of children with disabilities. We hope DOJ will step in to stop that from occurring,” said Karyn Rotker, senior staff attorney with the ACLU of Wisconsin.

For their part, officials at the Wisconsin Department of Public Instruction said they will fully cooperate with any Justice Department inquiry.

“Certainly, our data points to large discrepancies in student populations with formally identified special education needs between Milwaukee Public Schools and the private schools participating in the Milwaukee Parental Choice Program. And, we have expressed this fact and our concerns to state elected leaders,” says Patrick Gasper, a spokesman for the department.