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By Ariel Jao

A central Indiana teacher says his former school district forced him to resign following a disagreement over a policy that calls for teachers to address transgender students by their preferred name rather than their birth name.

Former Brownsburg High School orchestra teacher John Kluge, 28, said the Brownsburg Community Schools policy goes against his religious beliefs and violates his constitutional rights, the Indianapolis Star reported.

"I’m being compelled to encourage students in what I believe is something that's a dangerous lifestyle," he said. "I’m fine to teach students with other beliefs, but the fact that teachers are being compelled to speak a certain way is the scary thing."

Students must have written consent from a parent and doctor to request the name change, according to district documents.

LGBTQ community advocates say the practice is a sign of respect and isn't about religion or politics.

“Using a trans student’s chosen name is an invaluable support. Educators need to lead by example with respect for students’ identities, names, and pronouns," said Becca Mui, education manager at LGBTQ student advocacy organization GLSEN. "Teachers maintain an invaluable role in creating positive learning environments for all students. If John Kluge couldn’t model this respect for his students, he wasn’t creating a classroom environment where all of his students could thrive.”

Sam Brinton, head of advocacy and government affairs for The Trevor Project, a national nonprofit focused on suicide prevention in LGBTQ youth, said discrimination or a lack of support "can have a serious impact on the mental health of LGBTQ youth."

"Transgender and gender-expansive youth spend a significant part of each and every day in the classroom. Their safety and security make those hours a time of growth or a time of crisis," Brinton told NBC News. "Everyone deserves to be called by their name, and in doing so teachers are able to effortlessly respect their students and enable them to live authentically in an environment of their peers."

A representative from the Brownsburg Community School Corporation said Kluge “voluntarily submitted his resignation prior to the end of the school year.”

“The resignation was accepted by the administration,” the representative said in a statement, adding that the school district “complies with all state and federal laws.”

Kluge, however, has challenged that assertion, saying he submitted a tentative resignation letter because officials threatened to fire him. He said he had requested to withdraw the letter.

"They're acting as if I have (resigned), even though I'm pleading, 'No,'" he said. "I'm not dead yet. I still want to work here."

The Indiana Family Institute, a conservative research and education organization, has started a letter-writing campaign to support Kluge. The group is urging people to email Brownsburg High School’s administration to renew his position for the upcoming school year with a “faith-based accommodation previously agreed upon.”

Kluge said he reached a compromise with school administration that allowed him to refer to all students by their last name this past school year. He said administrators informed him a few months ago that he would no longer be allowed to do that.

The Indiana Family Institute's letter-writing website includes a statement from Kluge, where he says his classroom “responsibility includes the overall well-being” of his students.

"I view my responsibility to students in my community as more than just helping them become the best musicians they can be, though I certainly devote a considerable amount of time and effort to that worthy goal,” Kluge stated. “I wish to remain a teacher in good standing with the administration. However, as much as I love my job and would desire to keep it, I cannot take actions that could encourage harm to the students in my care and provide a poor example for others. I ultimately must submit my conscience to a higher authority."

Kluge, who had worked in the Brownsburg district for four years, says he plans to appeal to the school board Monday to get his job back.

Associated Press contributed.