More than 100 members of Congress have signed on to a bipartisan letter calling on President Donald Trump to reinstate transgender protections for students.

The Obama-era guidance from the Department of Education with the support of the Department of Justice instructed public schools to allow transgender students to use the bathroom of their choice. Trump revoked the policy last month, saying that he believes the issue belongs to the states.

(Related: Trump rescinds Obama-era guidance on transgender students.)

Out Congressman Marc Pocan of Wisconsin and the Human Rights Campaign (HRC), the nation's largest LGBT rights advocate, organized the effort.

“The federal guidance issued in May 2016 pertaining to transgender students reflects over a decade of case law and proven best practices from schools around the country,” the letter states. “The Departments issued this guidance at the request of educators across the country seeking clarification about how to best comply with existing laws. National leaders in education – including the leading associations of teachers, principals, pediatricians, and school counselors and psychologists – supported this clarification.”

“Title IX provides transgender students the right to equal treatment in accordance with their gender identity. Unfortunately, rescinding this guidance only serves to confuse school administrators and take away a vital tool for students and their families who want to be treated with dignity and respect. Further, this action sends the wrong message – a very dangerous message – to transgender youth and their peers.”