SACRAMENTO . (AP) — Gov. Jerry Brown on Sunday announced that he had vetoed legislation that would have provided overtime pay, meal breaks and other labor protections to an estimated 200,000 caregivers, nannies and house cleaners in California.

Brown called their work a “noble endeavor” and said they deserve fair pay and safe working conditions.

But the Democratic governor said the bill “raises a number of unanswered questions,” prompting him to reject the measure. It was among dozens of bills he acted on in the final hours before his midnight deadline to consider bills sent to him this fall by the Legislature.

Advocates said the legislation, dubbed the Domestic Workers of Bill of Rights, is necessary to protect a primarily female, immigrant workforce from abuse. They were successful in persuading New York lawmakers to pass similar legislation in 2010.

Among other things, the bill would have required that live-in workers be compensated if their rest period was interrupted during an eight-hour period and eased eligibility requirements for workers’ compensation.

The California Chamber of Commerce and other business interests opposed AB889. They argued that labor laws carve out an exception for domestic workers for a reason: providing meal breaks and uninterrupted rest periods for caretakers is impractical at best and dangerous at worst.

It was unclear how the legislation by Assemblymen Tom Ammiano, D-San Francisco, and V. Manuel Perez, D-Coachella, would have been enforced and whether it would have extended to part-time workers such as baby sitters. It called for the Department of Industrial Relations to set regulations by January 2014.

Brown outlined his own list of eight questions in a veto message.

They include the effect of increased costs he said could burden the disabled and elderly and their families. He also suggested the additional cost could mean fewer jobs for domestic workers and strain state regulators trying to enforce the requirements. Moreover, he said, a drafting error would have cost the state more than $200 million annually because the bill would have applied to In-Home Supportive Service workers.

“In the face of consequences both unknown and unintended, I find it more prudent to do the studies before considering an untested legal regime for those that work in our homes,” Brown wrote.

California has become a focal point in the national debate over domestic worker protections because of its size and large immigrant workforce. The bill has drawn some high-profile support, including a videotaped endorsement from comedian and “Parks and Recreation” star Amy Poehler.

The National Domestic Workers Alliance— an advocacy group with 35 local affiliates around the country— has used popularity of the Oscar-nominated film “The Help” to power a national campaign that urges fans to “be the help.” The group is helping promote similar laws in Massachusetts, Illinois and Hawaii.

New York is the only state that already has implemented union-style rights for domestic workers. Those regulations have led to back pay and overtime penalty awards, according to the Urban Justice Center, which provides legal assistance to domestic workers in Manhattan.

Last year, President Barack Obama proposed giving home aides additional labor protections such as overtime pay. The Labor Department took comments on the change, which is now under review by the White House Office of Management and Budget.

Household workers and agricultural laborers were left out of the 1935 National Labor Relations Act that established basic labor protections so the legislation would win support from Southern lawmakers.

The California bill was introduced in 2011 but stalled in the Senate for a year before passing both houses on party line votes.

“For decades we have tirelessly cared for California’s homes, children, the elderly, and people with disabilities without the protection of basic rights,” Sylvia Lopez, a worker with the California Domestic Workers Coalition, said in a statement. She called Brown’s veto “a huge disappointment.”

Ammiano, in a statement distributed by the coalition, said Brown “missed an opportunity to prove himself as a leader in civil rights.”

Democrats argued that workers who toil within homes already face a litany of woes, including low wages and lack of job security, and should enjoy the same legal protections as other laborers.

Republicans said the legislation was intended primarily to create a new class of employees for unions to organize and said it ignored the realities of caretaking jobs.

The bill has exemptions for workers who are caring for the developmentally disabled and also excludes baby sitters under age 18.

Home health and personal care aides are among the fastest-growing jobs in the country, according to the U.S. Labor Department.