The Washington Teachers’ Union said it told its members to ignore a school system letter emailed this week asking staff members to select whether they plan to teach in person in the upcoming months or stay home.

The union says the wording in the questionnaire is threatening and advised teachers to refuse to complete it until an agreement is reached about reopening buildings. But the school system letter accompanying the survey said that if it were not returned by Monday afternoon, the default response would be a willingness to teach in person.

The union demands include hazard pay during the first three phases of recovery, a suspension of standardized testing and teacher evaluations, and certain safeguards in every school building. The union says teachers should not be required to teach in person.

The school system emailed the questionnaire to thousands of employees Tuesday — days before the mayor is expected to make a decision on whether some students will return to classrooms in November.

It’s the latest in disagreements between the union and the chancellor since March over how and when teachers and students should return to school buildings, with few signs of progress.

“We are not obstructing a return to teaching,” Washington Teachers’ Union President Elizabeth Davis said. “We want answers on how it is going to be done safely.”

But if teachers are unwilling to return to school, it would complicate — and possibly torpedo — any plans of reopening buildings soon. The pandemic has drained the city’s finances, and the school system would need people to supervise and teach children in classrooms.

Chancellor Lewis D. Ferebee and the school system sent a similar survey to teachers in late June — when opening schools for in-person instruction in August was being considered but was rejected at the last minute. That survey was also met with backlash.

Mayor Muriel E. Bowser (D) has said it is safe to reopen schools and she wants to bring students back in a hybrid model on Nov. 9, the beginning of the second grading period. She has said “workforce readiness” is one challenge that has prevented campuses from reopening.

While many parents say the city is not ready to reopen buildings, a growing number feel it is safe and now is the time to return at least some students to classrooms.

The chancellor did not comment on the union demands. “Throughout the course of this pandemic, we have engaged our union partners and their members around the preferences and supports needed to safely reopen,” Ferebee said in an emailed statement to The Washington Post. “Through surveys and other engagement, we have received critical feedback that has contributed to our robust planning efforts.”

In the survey, teachers would indicate whether they seek to continue working 100 percent virtually because they are at high risk for complications if they contract the virus, they live with someone who is considered high risk or they have a dependent they need to supervise at home.

Teachers who are not considered high risk — or do not live with someone who is — but still want to be considered for all-virtual learning would be considered for remote work on a first-come, first-served basis of completing and submitting the survey. School staff members who fail to complete the survey by Monday afternoon would automatically be considered available for in-person teaching, the letter from school system said.

Davis said she had thought she and Ferebee planned to work on the questionnaire together and was frustrated that it was emailed without her input.

Based on the wording of the letter, she said it is unclear whether staff would be forced to take medical leave if they are unable to return to classrooms.

Samantha Brown, a teacher at Coolidge High in Northwest Washington, said she will not complete the survey until the chancellor agrees to the union demands. Specifically, she wants the chancellor to agree to comply to safeguards in each school building that would include face shields for adults, a full-time nurse on campus and upgraded air filters.

Brown is not considered high risk but said she is a Black woman during a pandemic that has disproportionately impacted Black Americans. She lives near her school in a ward with a high population of Black and Hispanic residents who have been hit hard by the virus.

“I thought it was disgusting,” Brown said of the letter. “Virtual learning was meant to be something to protect people. So what’s the message that is being sent to people in the building? That they are not important? That they don’t matter? Because they didn’t fill out the survey fast enough?”

Bowser and Ferebee announced on Monday that 13 schools in the traditional public school system would reopen this month for small groups of students. But it’s unclear how many of these plans include unionized teachers. Davis said she is unsure, and the school system also could not provide a number. Because these schools are intended to serve as “support centers,” teachers are still responsible for their virtual lessons and many of the staff members running these programs are not school system teachers.