Oklahoma’s Republican Attorney General Gentner Drummond on Friday sued to stop a state board from establishing and funding what would be the nation’s first religious public charter school after the board ignored Drummond’s warning that it would violate both the state and U.S. constitutions.

Drummond filed the lawsuit with the Oklahoma Supreme Court against the Oklahoma Statewide Virtual Charter School Board after three of the board’s members this week signed a contract for the St. Isidore of Seville Catholic Virtual Charter School, which is sponsored by the Archdiocese of Oklahoma City.

“Make no mistake, if the Catholic Church were permitted to have a public virtual charter school, a reckoning will follow in which this state will be faced with the unprecedented quandary of processing requests to directly fund all petitioning sectarian groups,” the lawsuit states.

The school board voted 3-2 in June to approve the Catholic Archdiocese’s application to establish the online public charter school, which would be open to students across the state in kindergarten through grade 12. In its application, the Archdiocese said its vision is that the school “participates in the evangelizing mission of the Church and is the privileged environment in which Christian education is carried out.”

The approval of a publicly funded religious school is the latest in a series of actions taken by conservative-led states that include efforts to teach the Bible in public schools, and to ban books and lessons about race, sexual orientation and gender identity.

Oklahoma’s Constitution specifically prohibits the use of public money or property from being used, directly or indirectly, for the use or benefit of any church or system of religion. Nearly 60% of Oklahoma voters rejected a proposal in 2016 to remove that language from the Constitution.

A message left Friday with Rebecca Wilkinson, the executive director of the Oklahoma Statewide Virtual Charter School Board, was not immediately returned, although Wilkinson has said previously she wouldn’t comment on pending litigation.

A group of Oklahoma parents, faith leaders and a public education nonprofit already filed a lawsuit in district court in July seeking to stop St. Isidore from operating as a charter school in Oklahoma. That case is pending.

Oklahoma’s Republican Gov. Kevin Stitt, who earlier this year signed a bill that would give parents public funds to send their children to private schools, including religious schools, criticized Drummond’s lawsuit as a “political stunt.”

“AG Drummond seems to lack any firm grasp on the constitutional principle of religious freedom and masks his disdain for the Catholics’ pursuit by obsessing over non-existent schools that don’t neatly align with his religious preference,” Stitt said in a statement.

Drummond defeated Stitt’s hand-picked attorney general in last year’s GOP primary and the two Republicans have clashed over Stitt’s hostile position toward many Native American tribes in the state.

The AG’s lawsuit also suggests that the board’s vote could put at risk more than $1 billion in federal education dollars that Oklahoma receives that require the state to comply with federal laws that prohibit a publicly funded religious school.

“Not only is this an irreparable violation of our individual religious liberty, but it is an unthinkable waste of our tax dollars,” Drummond said in a statement.

The National Alliance for Public Charter Schools, a nonprofit organization that supports the public charter school movement, released a statement Friday in support of Drummond’s challenge.