OAKLAND — First San Diego. Then Los Angeles. And now Oakland Unified School District is the latest school district to be slapped with a lawsuit by a charter school association with this message: Make space for charter schools in your district facilities as required by law.

The California Charter Schools Association filed the lawsuit Tuesday against OUSD to obtain a court order requiring it to comply with Prop. 39, a state law passed in 2000 that requires that school districts share facilities with all public schools, including charter schools.

The law states that school districts must provide school space in an area where charter schools want to locate, at a site that’s reasonably equivalent to school sites attended by students in the area, and ensure those classrooms are all located at a single site, rather than spread across multiple locations, according to the association’s CEO Jed Wallace. Wallace contends that the association had no alternative to filing the lawsuit after repeated efforts to work with the district regarding facilities for charters had yielded insufficient cooperation and inadequate space.

“Over a year ago, OUSD promised to improve Prop. 39 offers to charter schools, yet this year’s offers are worse then ever,” Wallace said. “OUSD’s offers violate the law on every front, and most don’t even come close to meeting the needs for students. We are fully committed to ensuring that charter students have fair and equal access to the classroom space across the state.”

In a statement, Superintendent Antwan Wilson said the district stands by its continued commitment to the letter and spirit of Prop. 39. Wilson said the district has a productive relationship with the charter association, and once it receives the lawsuit officially, it will respond accordingly.

“We are committed to ensuring equitable access to high quality public school instructional facilities for all Oakland public school children,” Wilson said. “We also believe that all public schools — district and charter — must implement equitable practices in their service of students.”

Oakland also has one of the highest charter school student enrollments in the state, with slightly more than 12,000 students attending one of 38 charter schools during the 2014-2015 school year, about 23 percent of total enrollment, according to the California Department of Education. Among the charges leveled at the district is that it ignored clear instructions provided in a California Supreme Court opinion from April 2015 on a lawsuit filed by the association against the Los Angeles Unified School District. The instructions, which apply to all public school districts in California, state that the L.A. district’s methodology in sharing its facilities with charter schools was not legal or fair, said Ricardo Soto, an attorney for the charter association.

The complaint contends that “Prop. 39 does not give school districts the discretion to refuse to make facilities offers to charter schools, nor does Prop 39 allow a district to serve itself first and offer only the leftovers, if any, to public school kids in charter schools.”

Wallace said that more of the half of the facility offers extended by the Oakland district to charter schools next year were split over more than one campus. For example, an offer made to Envision Academy was split over three sites, and American Indian Public Middle School received an offer split over seven campuses, he said.

Campus relocations put school students under enough stress without forcing them to go to seven spots spread across the city, Wallace said.

“We would like the school district to begin making these offers the schools are entitled to under law, because what these kids deserve is a sense of certainty that the school they love will continue to operate and succeed,” he said.

Contact Joyce Tsai at 925-945-4764. Follow her at Twitter.com/joycetsainews.