A group of 40 House Democrats have described “grave concerns” over the Trump administration’s secretive program of deportation flights and demanded the Federal Aviation Administration (FAA) address allegations of mistreatment and inhumane conditions on ICE charter jets.

In a letter shared with the Guardian and addressed to the FAA administrator, Bryan Bedford, the lawmakers describe the “urgent need for transparency” over ICE’s expanded use of commercial airliners to transfer detained immigrants and its “inappropriate and dangerous” efforts to shield these flights from public scrutiny.

“Credible reports indicate that individuals have been placed on flights without notice to counsel or family members, effectively disappearing from public view when flights are inappropriately shielded from tracking systems,” the letter states. “Families are left searching for their loved ones, and attorneys are denied meaningful opportunities to intervene, raising serious due process concerns.”

The letter references an investigation by the Guardian, based on leaked flight data, which revealed the Trump administration transported detained immigrants in ways that routinely violated their constitutional rights. The reporting also identified allegations of abuse and rights violations at a private detention center in Alexandria, Louisiana, a central node in the administration’s deportation program.

The Trump administration’s hardline immigration agenda saw a surge in the number of ICE flights during 2025, according to monitoring by human rights groups that tracked an 84% increase from 2024.

“Concerningly, information regarding these [ICE] flights is nearly impossible to find, which undermines congressional oversight and prevents the public from understanding the scope and conditions of these flights,” the letter states.

The Trump administration has previously described claims of “hidden” or “weaponized” transfer and deportation flights as “categorically false” and argued its detention centers have “higher standards than most US prisons”.

The lawmakers ask the FAA to provide a detailed report of “all ICE air operations” since Trump was sworn into office, including flight origin and destination data as well as how many passengers were held onboard each flight. It addresses reporting by the Associated Press, which revealed how dozens of charter jets used for deportation flights were granted unusual permission by the FAA to block certain data, including tail numbers, from public flight tracking sites – making it harder to monitor ICE air operations in public.

“This transparency is important for the American people to understand what is happening every single day because there are so many violations of due process and legal rights happening that if people knew about them they would find it deeply problematic,” said the New Jersey congressman Rob Menendez, the letter’s lead author. “We want people to understand what is happening on their dime.”

The signatories also include the Texas congresswoman Jasmine Crockett, who authored a bill earlier this year aiming to block airline operators from hiding their tracking data while carrying out federal government services, as well as co-author Illinois congresswoman Delia Ramirez and New York congressman Jerry Nadler, the ranking member on the House judiciary committee.

The letter also calls on the FAA to provide detailed information on how the agency assesses humanitarian conditions on ICE flights, including the controversial use of full body restraints during deportation flights. The lawmakers ask the FAA how restraining passengers in this manner affects evacuation and emergency procedures onboard and how ICE officers and flight attendants are trained to handle such scenarios.

The Trump administration has previously described its use of restraints on ICE flights as “long-standing, standard ICE protocol” designed to “ensure the safety and well being of both detainees and the officers/ agents accompanying them” and argued the practices are “fully in line with established legal standards”.

Menendez, who sits on the influential energy and commerce committee, said he expected representatives from airline companies working with ICE as well as private companies operating detention centers to face greater pressure to testify before Congress should Democrats win back control of the House following the midterm elections later this year.

“We are putting pressure on now. But when we have the majority and the gavels there is so much more work and oversight that we will be able to do to demand and get accountability for the American people so all options will be on the table,” Menendez said.

“People who think they can do this [immigration detention and transfer] work without there being any consequence are wrong.”