Five Bozeman, Montana residents have asked a judge to invalidate an ordinance prohibiting discrimination based on sexual orientation and gender identity in the areas of employment, housing and public accommodations.

Bozeman became the fourth Montana city to outlaw such discrimination when city leaders adopted the ordinance in June, the Bozeman Daily Chronicle reported.

Plaintiffs claim in their lawsuit that the city does not have the authority to enact such a law because it is preempted by state law. Montana's non-discrimination laws do not cover sexual orientation and gender identity.

The lawsuits describes plaintiffs as “members of a larger class of similarly concerned and aggrieved citizen-taxpayers” who may be affected by the ordinance.

Opponents of the ordinance hinted at a lawsuit while the law was being debated.

“This issue before the city council right now is ripe for a lawsuit,” Jeff Laszloffy, president of the Christian conservative Montana Family Foundation, said during a rally in April.