The fight to get the U.S. to stop detaining transgender immigrants in men’s immigration detention centers has reached the Capitol building in D.C.

This week 35 members of the House of Representatives—all Democrats—sent a letter to Secretary of Homeland Security Jeh Johnson urging him to end the detention of LGBT undocumented immigrants.

The issue gained attention this week when Jennicet Gutierrez, a transgender undocumented immigrant, interrupted Obama at a White House pride event and also called for an end to the practice Files

“These individuals are extremely vulnerable to abuse, including sexual assault, while in custody, in particular, transgender women housed in men’s detention facilities,” read the open letter addressed to Secretary Johnson.

Among the U.S. representatives that signed the letter were Barbara Lee (D-Calif.), Frederica Wilson (D-Fla.), John Lewis (D-Ga.), Sheila Jackson Lee (D-Texas), and Raúl Grijalva (D-Ariz.)

The members of Congress highlighted that Immigration and Customs Enforcement (ICE) acknowledges that LGBT immigrants are vulnerable to sexual harassment and assault while in detention.

“The fact that ICE is ignoring its own policies not to detain individuals who will be in harm’s way is ultimately enabling the sexual assault of LGBT individuals. ICE has the authority to stop this – in fact, ICE agents have to overrule their own recommendations every time they do not stop it, and that is completely unacceptable,” Rep. Raúl Grijalva of Arizona told Fusion.

“We will respond directly to the members regarding this issue,” ICE spokesperson Gillian Christensen told Fusion.

The Department of Homeland Security Office of the Inspector General and ICE’s Office of Professional Responsibility investigates all allegations of misconduct, including sexual abuse.

A 2014 Fusion investigation found some 75 transgender prisoners are detained by ICE every night, less than one percent of the 34,000 people held in detention. Yet trans victims made up 1 out of 5 confirmed instances of sexual assault in immigration detention facilities.

“This is something that is important and needs to be addressed,” Rep. Michael Honda of California told Fusion.