OKLAHOMA CITY (AP) — City workers in Oklahoma’s 13 largest cities likely would lose their collective bargaining rights under a Republican-backed bill approved Monday by a Senate committee.

The legislation would repeal the Municipal Employees Collective Bargaining Act, a law approved in 2004 that requires Oklahoma cities with more than 35,000 residents to collectively bargain with their employees. If approved, cities would have the option of whether to collectively bargain, said Sen. Cliff Aldridge, who sponsored the bill.

“This basically sends it back to permissive language,” said Aldridge, R-Midwest City.

The Senate General Government Committee approved the bill on a 5-3 party-line vote.

State workers in Oklahoma, with the exception of teachers, do not have collective bargaining rights. Aldridge’s bill would not affect collective bargaining requirements for municipal police and firefighters in the state.

Carolyn Stager, the president of the Oklahoma Municipal League, said collective bargaining rights of city employees was an “unfunded mandate on cities and towns” because it generally requires cities to pay more in salary and benefits to its workers. She said those decisions should be made by elected officials, such as city councils or mayors.

But Matt Thomas, a Midwest City water treatment center worker, said collective bargaining is more about workers having a voice on issues important to them. He said a new contract approved last year requires the city to buy heavy coats and coveralls for employees who work outside and provide safety spikes for their boots to protect them from slips and falls during snow and ice.

“A lot of it has nothing to do with wages at all,” said Thomas, chairman of the Midwest City chapter of the American Federation of State, County and Municipal Employees Union. “It’s about safety and having a voice in the workplace.”

Republicans ushered in huge gains across Oklahoma in November’s elections, extending their majorities in the House and Senate and capturing every statewide elected office on the ballot, including the governor’s post. Sen. Andrew Rice, the Democratic leader in the Senate who opposed the bill, said those gains had more to do with the unpopularity of President Barack Obama and divisive issues including abortion, immigration and gun rights.

“Thirty years ago, your blue-collar union workers in Oklahoma voted pretty faithfully Democratic, but what’s moved them away from the Democratic Party have been national wedge issues like abortion, these sorts of things,” said Rice, D-Oklahoma City. “I think the wedge issues are going to run their course, and people are going to ask who is out there standing up for the basic rights of the working man.”

Thomas, a registered Republican, agreed.

“I thought Republicans understood the needs of labor, but I guess I was wrong, judging by today’s vote,” he said.