The US supreme court will hear arguments on Tuesday over a challenge brought by two Catholic preschools in Colorado, arguing that they should be admitted to the state’s free education system despite their rejection of children with LGBTQ+ parents.

A decision in the case, St Mary Catholic Parish v Roy, could reshape the relationship between religious freedom and nondiscrimination laws in the US.

The Catholic preschools claim that they been shut out of a 2023 state funding program that provides 15 hours per week of state-funded preschool and want the same benefits extended to them. Colorado says that the schools “remain welcome to participate in” the program but only if they agree to the same equal-opportunity requirements that apply to all other publicly funded preschools–public and private, secular and religious”.

But to join the program, Colorado says, the schools must consent to “provide eligible children an equal opportunity to enroll and receive preschool services regardless of race, ethnicity, religious affiliation, sexual orientation, gender identity, lack of housing, income level, or disability”.

The plaintiffs argue that making funding contingent on accepting that agreement amounts to unlawful religious discrimination under the first amendment guaranteeing religious freedoms.

The case – in essence a clash between religious freedom and non-discrimination laws – has been making its way up the court system. A lower appeals court ruled for the state but acknowledged that the highest court has previously held that states “cannot categorically withhold those funds from religious institutions”.

In the lower court’s view, the rulings do not apply to the current case because Colorado “did not exclude” religious preschools from its funding program and had “welcomed and actively solicited their participation”.

The archdiocese claims that the state allows participating preschools “to discriminate in favor of LGBTQ families and other groups”, such as “gender-nonconforming children”, “children of color”, or members of “the LGBTQ community”.

Nicholas Reaves, counsel at the Becket Fund for Religious Liberty, a firm that litigates religious liberty cases, told the National Catholic Reporter that Colorado had “denied families … the ability to use that funding at Catholic preschools, simply because those preschools have religious beliefs the state doesn’t like”.

In an amicus brief submitted to the court, the US Conference of Catholic Bishops argues that Colorado had disqualified the preschools “solely because of their adherence to Catholic doctrine”.

The lower court’s decision, the conference said, “will embolden other states and municipalities to discriminate against religious adherents’ rights by enacting ostensibly neutral statutes that discriminate in fact”.

If allowed to stand, it added, “the resulting harm to the nation’s social support infrastructure would be immense.”