A Colorado governor has been sued by six sheriffs in a federal court on Thursday claiming that the state laws legalizing marijuana will force them to violate federal law. Joining in the lawsuits are neighboring states of Kansas and Nebraska. They say the marijuana law creates a “crisis of conscience “and puts other states on an economic burden.

“This suit is about one thing — the rule of law,” Larimer County Sheriff Justin Smith said during a news release. “The Colorado Constitution mandates that all elected officials, including sheriffs, swear an oath of office to uphold both the United States as well as the Colorado Constitutions.”

The group of sheriffs want to know how they will enforce and uphold both state and federal law since the two are contradicting each other.

“As an elected sheriff I take an oath to uphold the constitution of the United States and the constitution of the state of Colorado. Well, those two are in conflict with one another and so the issue is … this is really a rule of law question … so what we’re asking is which oath would you like us to uphold and which laws would you like us to enforce?” Elbert County Sheriff Shayne Heap said.

Marijuana in Colorado was legalized in 2012 through Amendment 64 which Colorado voters passed in November 2012. Half of the sales recorded last year were to people from the neighboring states. Mike Elliott, marijuana industry group attorney said “Hearing the sheriffs talk about that they have to enforce federal law … well, they don’t have to enforce federal law. These are people who work for the state. They’re supposed to be enforcing state law and so I don’t see the conflict.”

The state of Colorado has until March 27 to respond to the lawsuit.