LINCOLN, Neb. (AP) — Lincoln’s fire chief says he’s denied a union challenge on the use of a pickup truck for medical calls.

The Lincoln Firefighters Association filed a grievance last month against Lincoln Fire and Rescue Chief John Huff’s order that medical calls to the city’s busiest station be answered in a pickup truck instead of a fire engine. The group says the order endangers firefighters and violates the collective bargaining agreement.

Huff says the May 12 order for crews at Station 1 was more efficient and saves money. He also says his order doesn’t overstep his contractual bounds.

Union leaders have until June 26 to decide whether to proceed to arbitration.