SALMON, Idaho (Reuters) - Hundreds of union supporters linked hands to form a chain around Idaho's Capitol in Boise on Wednesday to protest a bill passed by the state legislature to strip public school teachers of most collective bargaining rights.

The 12,000-member Idaho teachers union organized the rally in Boise and a dozen other cities in what the group says is likely a doomed bid to persuade Republican Governor Butch Otter not to sign the measure into law.

The bill crafted by the state's schools chief, Tom Luna, and endorsed by Otter cleared the Republican-controlled Legislature on Tuesday.

It would limit collective bargaining to salaries and benefits and disallow negotiations on such issues as class size and teacher workload. It also would abolish teacher tenure and limit contracts to one year.

Its passage came as Wisconsin and other states have been experiencing high-profile standoffs over Republican moves to limit union rights for public workers.

Republican lawmakers say curbing unions will save money and restore local control, giving school boards and administrators more flexibility to hire and fire teachers. Opponents have accused the GOP of seeking to muzzle teachers.

Protesters ringing the Capitol on Wednesday gagged their mouths with red kerchiefs when they were not chanting slogans like "Respect, fairness and voice."

"They believe if you take away the rights of teachers, the union is going to go away," teachers union President Sherri Wood told Reuters by telephone.

"We've been here 119 years and we will continue to be here to fight for our teachers and for our school children."

(Editing by Steve Gorman and Jerry Norton)

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