In what the Cherokee Nation described as “an attack on the very sovereignty of our nation,” several pharmaceutical distributors and retail pharmacies have asked a federal judge to prevent a lawsuit against them over the opioid addiction epidemic from proceeding in tribal court.

The companies' complaint, filed Thursday in the U.S. District Court for the Northern District of Oklahoma, alleges that the Cherokee Nation district court does not have jurisdiction to civilly enforce the federal Controlled Substances Act, nor does the alleged behavior “threaten either tribal governance or internal relations among tribe members.”

“None of [the defendants] are tribal members or tribal corporations,” the 31-page complaint said. “Moreover, none of [their] conduct at issue occurred in Indian country. That should be the end of the jurisdictional inquiry.”