Montgomery County teachers and support workers are protesting staff shortages in Maryland’s largest school system, saying they are exhausted and stressed out less than two months into the school year.

Leaders of two employee unions led a rally outside school system headquarters Tuesday evening, supported by a long line of members driving cars in a procession with headlights on and horns blaring.

Car windows were taped with signs referring to “skeleton crews” in schools and teachers “drowning” in the workload. Teacher working conditions are student learning conditions, other signs said.

Amid the staffing shortages, educators say they are being tapped to cover other classes during their lunch and planning periods. They say they get less support from principals, who are tasked with public health duties related to the continuing pandemic.

And nearly half of requests for substitute teachers in Montgomery County go unfilled, according to the school system data — which educators describe as a major problem.

“We are being set up for failure, and our students are being set up for failure,” said Jennifer Martin, president of the Montgomery County Education Association, the 14,000-member teachers union. “The demands are unreasonable.”

Martin said school system leaders failed to plan for the realities of the school year, and workers are at a breaking point. She called for greater collaboration between school system leaders and employee unions.

Teachers can get $15 for covering another educator’s class during what should be their planning period, Martin said, but she described the money as “not a professional salary” and said educators still are left with their usual responsibilities.

“What we really need is time to do our jobs,” she said.

Pia Morrison, president of Local 500 of the Service Employees International Union (SEIU), which represents almost 9,000 school system support staff, pointed to fallout for her members too: Bus drivers are doing extra runs because of staff shortages, she said, and other employees are “literally trying to do the work of an additional person.”

“The staff are being asked to do more work,” in a system that is down hundreds of people, she said.

School system officials in Montgomery County acknowledge staffing shortages — a problem that is widespread in the region and the nation.

The system, with more than 200 schools and about 24,600 employees, has vacancies for 325 teachers, about 105 paraeducators, nearly 100 other support staff and about 120 bus drivers, according to recent school system data.

Montgomery County schools spokesman Christopher Cram agreed that the system has more jobs than people willing to fill them.

“People are doing more work and stepping up to ensure administratively schools have what they need and students are getting the content they need but there is anxiety over increased workloads,” he said.

Still, he said, the system’s human resources department is working to recruit new personnel. The system continues to “actively and strategically” recruit highly effective teachers, he said, and is working with local colleges and universities to hire December graduates.

Bus driver shortages, he said, are being addressed by using supervisors and trainers to drive routes. But he said some drivers still need to make more than one trip to cover all of the system’s routes.

Union leaders say the school system could do more — especially since it has received an influx of federal funding to help ensure students get back on track with their learning.

That money is being used to support schools, including counselors and mental health professionals, Cram said. “But you still have to find people to fill those positions,” he said.

Kember Kane, a kindergarten teacher, said that educators are trying to make the best of a bad situation but the demands are overwhelming and not sustainable.

“You can’t ask someone on life support to run a marathon,” she said.

Union leaders are calling on the school system to restore planning time and comply with requirements to give educators a lunch break.

Cram said there is “no doubt that teachers are giving 100 percent and more,” but those who are not getting lunch periods or planning periods should “collaborate with their building leadership to ensure they are maintained.”

Chelsea Van Tassell, a middle school English teacher, said the school board has yet to acknowledge the gravity of the problem.

Students need high-quality classes and support, but teachers are becoming stretched worryingly thin, she said. “It’s pretty serious,” she said, “and it’s not going away.”