PHOENIX — The Arizona attorney general's office is preparing to launch investigations of counties, cities or towns that violate a new law forbidding them from passing local regulations like plastic bag bans that conflict with state law or the state Constitution.

Attorney General Mark Brnovich's office posted forms Friday for legislators to use to file complaints that trigger the probes.

Under the law that takes effect Saturday, a single lawmaker can trigger an investigation. If Brnovich finds a violation, the county has 30 days to repeal the regulation or they will lose all state shared revenue they receive.

The state sent nearly $1.1 billion from income and sales taxes to 91 cities and towns in the budget year that ended June 30, 2015.

The law was backed by most majority Republican lawmakers and signed by GOP Gov. Doug Ducey.

The Arizona League of Cities and Towns called the law heavy-handed and intrusive and had urged Ducey to veto it.

"The elimination of shared revenue from cities and towns is a crippling and unjust penalty since it represents an average of 40 percent of a city's general fund," said a letter to Ducey signed by the mayors of Tempe, Lake Havasu City and Chandler in their roles as league leaders in March.

Instead, Ducey signed the legislation, which was opposed by Democratic lawmakers but backed by all but four Republicans who voted on the measure in the Legislature.

Ducey had vowed in January in his state-of-the-state address to cut state-shared revenue to any city that adopted a minimum wage that was higher than the state's, even though the law allows that. Lawmakers took the threat much further, crafting a law that allows for a cutoff of funds for any ordinance or regulation conflicting with state law.

After Ducey signed Senate Bill 1487 on March 17, his spokeswoman said it ensures everyone in the state is playing by the same rules and avoids a patchwork of different laws.

The Republican-dominated Arizona Legislature has taken a firm stance in recent years against cities that enact laws popular in liberal enclaves, such as plastic bag bans and rules governing energy efficiency in buildings.