A federal appellate court has again sided with Enbridge Energy, denying Michigan Gov. Gretchen Whitmer's latest attempt to dismiss a lawsuit over the continued operation of the Line 5 oil pipeline. 

The decision by the Sixth Circuit Court of Appeals marks the third time the governor's argument for sovereign immunity has been rejected in the ongoing legal battle.

The Canadian energy company's lawsuit, which seeks to ensure Line 5 remains operational, was found by the court to fit an exception to sovereign immunity due to alleged violations of federal law. 

This ruling paves the way for the legal fight over the pipeline's future to continue, with a potential appeal to the U.S. Supreme Court as Whitmer's next option.

Line 5, owned by Enbridge, transports crude oil from northwest Wisconsin, through Michigan, and into Sarnia, Ontario, Canada. A significant portion of the 72-year-old pipeline runs under the Straits of Mackinac, connecting Michigan's Upper and Lower Peninsulas.

Michigan Attorney General Dana Nessel has been a vocal proponent of shutting down Line 5 since taking office in 2019, citing concerns from Native American tribes, environmentalists, and other groups who fear a catastrophic oil spill in the Great Lakes. 

Nessel maintains that Line 5 is primarily a Michigan issue and argues Enbridge is in violation of state environmental laws.

Enbridge, however, asserts the dispute is a federal matter and successfully moved Nessel's initial lawsuit, Nessel v. Enbridge Energy, to federal court. 

While the Sixth Circuit previously sided with Nessel on the jurisdiction of that specific case, this recent ruling reiterates the federal court's involvement in the broader legal challenges surrounding Line 5's future.