PORTLAND, Ore. (AP) — Teachers in Portland, Oregon, have voted to go on strike, their union announced Friday, in another sign of a growing national organized labor movement that’s seen thousands of workers in various sectors walk off the job this year.

The Portland Association of Teachers’ strike would start Nov. 1 unless an agreement with the school district is reached before then.

The union said nearly 99% of teachers voted in favor of the strike, with 93% of its members participating in the ballot.

Teachers have cited large class sizes, salaries that have not kept up with inflation and a lack of resources as key concerns. The union has been bargaining for months with the district for a new contract, which expired in June.

“Students need stability and experienced educators in our schools, but the high cost of living is pushing teachers to leave the district. I don’t know how I’m going to survive on a teacher salary in Portland and I’m at the top of the pay scale,” said Shannon Kittrick, a high school educator, in an emailed statement from the union.

Schools will close and there will be no classroom or online instruction if the strike takes place, according to the district, which said it wants to avoid such a scenario.

“We want to reach a fair, sustainable settlement, and we will stay at the bargaining table as long as it takes to get there. We ask our educators to stay at the table with us, not close schools,” Portland Public Schools said in an emailed statement.

The district is the largest in Oregon with roughly 45,000 students.

Public education has been gripped by a series of high-profile strikes this year.

In the Los Angeles Unified School District, the nation’s second-largest, workers including teachers’ aides, cafeteria workers and custodians walked out for three days in March to demand better wages and increased staffing, shutting down education for half a million students.

In Oakland, California, the union representing teachers, counselors, librarians and other workers went on strike for more than a week in May. In addition to typical demands such as higher salaries, it also pushed for “common good” changes, such as reparations for Black students and resources for students who are homeless.