Rocky Mountain Power filed a lawsuit Monday claiming that the Willard City Council wrongly terminated a conditional-use permit to construct electric transmission lines for a proposed $4.1 billion project through the Box Elder County community.

The company said in a news release that the council "denied" the permit they previously approved, without sufficient notice or due process. The release described the decision as contrary to state law and a violation "of the company's property and due process rights under both the Utah and U.S. constitutions and Utah's land use statute."

The transmission line "is essential to provide renewable and traditional electric power for delivery in Willard and to other Utah customers of Rocky Mountain Power," the utility said in a news release.

The company claimed in the release that construction on the project is already under way and Willard's actions "jeopardizes the entire project."

"We were stunned and disappointed by the city's action," said Mark Moench, Rocky Mountain Power senior vice president and general counsel, in the release. "Rocky Mountain Power worked diligently and in good faith for six months to comply with all conditions the city attached to its conditional use."

Last Thursday, the council voted to overturn its previous decision to issue a conditional use permit for construction of the power line project. Civic leaders expressed concern that the high-voltage power lines would pose a potential health hazard to nearby residents.

Jay Aguilar, Willard's city planner, told the Deseret News on Monday that the utility received conditional approval for the project from the council in November 2008, based on the presumption that Rocky Mountain Power eventually would provide details of the plan.

"Their position is, 'Well we got an approval back then,' " he said. "In their opinion … it's a formality to come back and do the review. That's not the way we're going to see it, obviously."

Rocky Mountain Power filed the complaint in Utah 1st District Court on Friday and is following that action with a motion for a preliminary injunction against the city, the release said. Rocky Mountain Power is seeking affirmation of the conditional-use permit and will seek damages from the city if the council's actions "results in the project's delay or additional costs to our customers." The injunction asks the court to authorize the company to begin construction immediately and prohibit Willard from interfering with the company's construction schedule.