A Phoenix-based conservative advocacy group is suing Tucson over the city's contracting preference for local businesses.
The suit filed Friday by the Goldwater Institute in Pima County Superior Court contends the preference violates constitutional provisions and a state law that protects the integrity of government procurement.
The preference enacted in 2012 allows city contracts to be awarded to local companies even if they aren't the lowest bidders.
The ordinance allows contracts with local businesses whose bids are up to 5 percent higher than the lowest bid. There are smaller preferences for Arizona companies outside the Tucson area and for local owners of national franchises.
Goldwater said it contends the preference hurts taxpayers, while city officials defend the ordinance as a way to keep money in the local economy.