(CNN) - The government shutdown could soon put the immigration enforcement arm of the Department of Homeland Security at risk of running out of funds and unable to pay contract dues.
Immigration and Customs Enforcement is tasked with, among other things, detaining and deporting undocumented immigrants in the United States. To do so, the agency contracts with private companies and county jails across the country. But, with shutdown talks at an impasse and no additional funding in sight, ICE is forced to work with what it already has in its coffers.
"ICE only has a finite amount of money that they had been appropriated and that ended on December 21," said Tracey Valerio, the former director of management at ICE, referring to the date when government funding expired. "If we go much more than a month or so, I would think that the money would run out."
Detention facilities are key to ICE's operations: As of January 1, more than 48,000 individuals were in ICE custody, surpassing the 40,520 detention beds for which it's received funding.
Because the agency only has access to those funds appropriated to them, it may need to work with contractors on a voluntary basis. Unless deemed necessary for public safety or to protect property, ICE may run afoul of the Antideficiency Act, which prohibits "accepting voluntary services for the United States, or employing personal services not authorized by law."
ICE has cited the safety of people and property as reason for continuing some of its activities.
"Many of ICE's law enforcement activities are deemed necessary for safety of human life or protection of property and therefore qualify for an exception to continue during a lapse of appropriation. This includes detention center operations," an ICE official told CNN.
Still, a shutdown could spur challenges for ICE contracts. Guidance from the Department of Homeland Security on lapse of appropriations explicitly states that "even when a contract, order, agreement or other transaction may be awarded or modified in order to preserve life or safeguard property, DHS cannot pay the contractor until appropriations are enacted." In this scenario, contractors can continue to work with the understanding that they will not get paid until the shutdown is over.
A spokesperson for CoreCivic, a private detention company, told CNN they continue to invoice the government, knowing that the payment will be delayed.
"We understand that the payment will be delayed until the government reopens," the spokesperson said, adding that CoreCivic employees are continuing to be paid.
Who ICE is holding in detention has also raised questions about whether the agency might run afoul of the Antideficiency Act. An individual who isn't deemed dangerous, for example, wouldn't be a safety risk and therefore shouldn't be held without funds appropriated. But the language leaves room for interpretation.
"The way language is written is protecting human life and property. Whether or not the people are in the facilities are considered dangerous or not, the facilities are protecting human life either way," said Travis Sharp, a research fellow at the Center for Strategic and Budgetary Assessments.
The longer the clock runs on the government shutdown, the more issues that are likely to arise as to who and how ICE can continue detaining individuals -- throwing a wrench in yet another of the Trump administration's efforts to crack down on immigration.