Tens of thousands of Kaiser Permanente workers have authorized a strike to begin at the end of this month if negotiations fail with the hospital chain.

About 98% of the SEIU-United Healthcare Workers West union voted to strike if a deal isn’t reached by Sept. 30, the union said in a Thursday press release.

“This could be the largest healthcare strike in U.S. history, as workers say Kaiser executives refuse to acknowledge the decline in patient service and care and negate the struggle of the workforce to keep up with the high cost of living in areas where Kaiser operates,” the union said.

In addition to the 60,000 members of SEIU-UHW, Colorado Kaiser employees also voted to authorize a strike, and Oregon Kaiser employees will unveil the results of their strike vote Thursday. Up to 85,000 workers in total could strike.

“For weeks, Kaiser sent us messages telling us to reject a strike,” Miriam De La Paz, who works at the Kaiser Permanente Medical Center in Downey, said in the statement. “Their millionaire executives implied we were imagining the delays in care our patients are experiencing and ignored the fact that our families are struggling more and more to keep up with the rising cost of living. Instead, workers are rejecting short staffing and inadequate pay, and we will be going on strike if Kaiser doesn’t stop committing unfair labor practices.”

The strike authorization comes 10 days after 23 health care workers were arrested while protesting outside a Kaiser hospital in Hollywood.

After that protest, Kaiser Permanente sent KTLA a statement saying they’re “committed to providing a positive, safe, and equitable work environment and to being a best place to work.”

“We remain committed to bargaining with our Coalition unions in good faith and in the spirit of partnership, working together to address the many complex issues at both local and national bargaining tables. We are confident that we will reach an agreement that achieves this goal before the national agreement expires on September 30,” the statement added.

Health care workers are far from the only ones striking or threatening to strike in what’s been called “hot labor summer.” In addition to the prominent writers and actors strikes, hotel workers, Los Angeles city employees, auto workers and others have gone on strike or threatened to do so.