Idaho's Republican governor on Thursday signed into law a measure that strips public school teachers of some major collective bargaining rights and does away with teacher tenure.
Butch Otter is the second governor to sign such a measure this year, after Wisconsin Governor Scott Walker signed legislation curbing that state's public workers union last Friday.
The Idaho law limits collective bargaining by the 12,000 teachers represented by the Idaho Education Association, the state teachers union, to salaries and benefits.
That means educators can no longer negotiate such issues as teacher workload and class sizes. It also does away with teacher tenure and limits contracts to one year.
In a statement accompanying the signing, Otter pledged the measure would "improve the ability of our public schools to fulfill their mission of educating Idaho's children."
The law comes amid high-profile battles in Wisconsin and other states with Republican governors and majority-Republican legislatures over measures seeking to curb unions, especially those for public employees.
Republicans say the measures are needed to gain control of deficit-ridden budgets. Democrats and their union backers say Republicans are ramming through union-busting proposals.
Restrictions on public sector unions have been introduced in states including Indiana, Ohio, Iowa, Michigan and Florida.
The push by Republican leaders in Idaho to limit the power of the teachers union sparked protests, including a walkout by high school students across the state.
Backers of the legislation denied it was aimed at unions.
During debate over bill, Republican Senator John Goedde said the measure restored local control since it gave school boards and administrators more flexibility to hire and fire teachers.
"This bill isn't about collective bargaining; it's about putting students first," said Goedde, a sponsor.
Opponents argued the GOP was seeking to muzzle teachers.
"Let's stop pretending this has anything to do with the classroom or our children," Democratic Representative Brian Cronin of Boise said during debate in the Idaho House.