By Brad Brooks

An Oklahoma school board on Monday approved the Catholic Church's application to create the first taxpayer-funded religious charter school in the U.S.

Opponents of the school have vowed a legal challenge which promises to be a long court battle testing the U.S. Constitution's concept of separation of church and state.

Oklahoma's Statewide Virtual Charter School Board approved the plan to create the St. Isidore of Seville Catholic Virtual School in a 3-2 vote.

The board in April had rejected the first plan submitted for the school, saying they needed more details, including on the special education department.

Roman Catholic organizers proposed creating St. Isidore to offer an online education for kindergarten through high school initially for 500 students and eventually 1,500.

Board members have emphasized repeatedly that they were not voting on the constitutionality of such a school, but only whether the application met the board's standards.

Charter schools are publicly funded, independently run schools established under the terms of a charter with a local or national authority.

Any legal fight could test the scope of the U.S. Constitution's First Amendment "establishment clause," which restricts government officials from endorsing any particular religion, or promoting religion over non-religion.

Church officials have said they hope the case will reach the U.S. Supreme Court, where a 6-3 conservative majority has taken an expansive view of religious rights, including in two rulings since 2020 concerning schools in Maine and Montana.

The school would cost Oklahoma taxpayers up to $25.7 million over its first five years of operation, its organizers said.

The idea came from the Catholic Archdiocese of Oklahoma City. The law school at the University of Notre Dame, a Catholic institution in Indiana, helped with the application.

(Reporting by Brad Brooks in Lubbock, Texas; Editing by David Gregorio)