Members of the Brookline Educators Union have overwhelmingly voted to go on strike, beginning Tuesday, over concerns about maintaining social distancing guidelines within school buildings.

During ongoing bargaining agreements, Union President Jessica Wender-Shubow urged school officials to formally commit to 6 feet of social distancing in classrooms and throughout schools.

Brookline Superintendent of Schools James Marini said he could not promise to maintain a 6-foot rule. He wrote in a statement to GBH News Monday that “taking any action that would limit our ability to adapt is irresponsible and would fly in the face of science and fact-based decision-making.”

Wender-Shubow said in an interview with GBH News Monday that the “school district wants to unilaterally allow the superintendent to decide how much social distancing there is based on his own personal interpretation of ‘best practices.’”

In August, the Massachusetts Department of Elementary and Secondary Education issued guidelines that a distance of 6 feet is “preferred whenever feasible,” but 3 feet would be a “minimum acceptable distance” when combined with masks and other safety measures.

“Dr. Marini has said repeatedly that he does not anticipate changing the 6-foot distancing unless something significant happens to change our understanding of best practices,” Marini’s statement reads. “This last part is key: best practices can change.”

The School Committee voted Monday to file a petition for the Massachusetts Department of Labor Relations to investigate the educators' proposed strike.

“They're bringing the Department of Labor against us rather than try to work this out,” Wender-Shubow told GBH News. “This is about a process, this isn’t about not working. … The teachers here were already feeling like things were not being handled in a responsible, even remotely predictable and transparent way.”

The School Committee asked the union to reconsider the strike, but Wender-Shubow said direct action is in the best interest of the union’s 1,200 members, 90% of whom voted Sunday night in favor of the strike.

“What would I say to all of those educators? What would I say to them that had changed? Nothing has changed,” Wender-Shubow said. “So what, they threatened me. We already knew that we were taking a risk, they should thank us for doing it. They should thank us for standing up for these kids and for one another. All we're asking for is process.”

More than 500 of the union’s members live in Boston, where Mayor Marty Walsh called for schools to roll back to remote learning after a spike in COVID-19 cases last month. “So you want people coming and going into the city, day in and day out, and you will not commit even to a process that is fair, to community standards,” Wender-Shubow said. “So we said, let’s say when the CDC and the Massachusetts Commissioner of Public Health say that we can relax those standards, we will then sit down with you and figure out the logistics, we’ll bargain with you. They said no.”

Though education unions and school committees in Arlington, Boston, Hanover, Hingham, Milton, Wellesley and Weston have reached agreements that include 6 feet of social distancing, Marini argued in his statement that flexibility will be necessary to ensure safety for students and staff members. “Because of this rapidly-evolving situation, [Public Schools of Brookline] must retain the ability to continue to adhere to best practices,” the statement reads. “At any point before the end of the school year, the optimal mix of protective measures may be very different and less reliant on distancing.”

Members of the teachers' union can’t move forward on those terms, Wender-Shubow said. “They feel so disrespected and so rightfully scared that there's nobody watching this, that all the public health stuff is just a little bit too arbitrary.”