John Kelly, who formerly served as President Trump’s chief of staff and homeland security secretary, joined other former homeland security secretaries in calling for the department they used to head to be reopened as the partial government shutdown enters its second month.

“Homeland security is national security,” the group wrote in a letter to Trump and Congress this week asking them to restore funding to the department, which is one of nine affected by the partial government shutdown. “DHS has a vital mission: to secure the nation from the many threats we face. This requires the dedication of more than 240,000 employees in jobs that range from aviation security, law enforcement and protective services, border security, emergency preparedness and response, and federal network security to stopping human trafficking, child exploitation and transnational criminal organizations. Their duties are wide-ranging, but their goal is clear — keep America safe.”

Kelly, who served as head of the agency until he joined Trump’s White House in July 2017, joined former DHS secretaries appointed by both Republican and Democratic presidents: Tom Ridge, Michael Chertoff, Janet Napolitano, and Jeh Johnson. The shutdown also affects the Justice, State, and Treasury departments.

The former secretaries noted that Congress has “consistently voted” to fund other national security agencies, including the Department of Defense, during government shutdowns. The Defense Department hasn’t been affected by the current shutdown. “DHS should be no different,” they wrote. “With today’s threats, there is no longer a distinction between the ‘away game’ and the ‘home game,’ which is why DHS and DoD work hand in hand to defend our country.”

Kelly’s signature on the letter comes as a bit of a surprise, given that it’s been just weeks since he left the White House and the shutdown began while he was technically still employed there. He has also been a hardliner on immigration — the issue Trump says is at the root of his refusal to sign a government funding bill — and infamously defended the Trump administration’s family separation practice by saying that children taken from their parents would be “taken care of — put into foster care or whatever.”

But Kelly has acknowledged that the border wall, for which Trump is currently demanding $5.7 billion, isn’t, in his eyes, the best idea.

“To be honest, it’s not a wall,” Kelly said in an interview with Los Angeles Times reporter Molly O’Toole in December.

He said that when he met with border agents as homeland security secretary, they told him they needed a “physical barrier in certain places” but also “technology across the board, and we need more people.”

“The president still says ‘wall’ — oftentimes frankly he’ll say ‘barrier’ or ‘fencing,’ now he’s tended toward steel slats,” he said. “But we left a solid concrete wall early on in the administration, when we asked people what they needed and where they needed it.”

The security risks the shutdown is created are getting a little scary

Air travel has become a particular point of concern amid the government shutdown. Transportation Security Administration agents, who are under DHS, are deemed “essential” employees during the shutdown and have to work without a paycheck. Many have been calling out sick. Air traffic controllers are also considered “essential.”

On Wednesday, three aviation unions — the National Air Traffic Controllers Association, the Air Line Pilots Association, and the Association of Flight Attendants-CWA — released a statement urging Congress and the White House to “end this shutdown immediately” and sounding the alarm about what might happen if they don’t.

“We have a growing concern for the safety and security of our members, our airlines, and the traveling public due to the government shutdown,” the unions’ leaders said. “This is already the longest government shutdown in the history of the United States and there is no end in sight. In our risk averse industry, we cannot even calculate the level of risk currently at play, nor predict the point at which the entire system will break. It is unprecedented.”

Unfortunately, it still appears there is no end in sight. The Senate on Thursday will take two votes to end the shutdown. Both are expected to fail.