Homeland Security shutdown concerns are rising as Congress tries to renegotiate a DHS spending bill that Republicans and Democrats are struggling to align on, with negotiations centering on how to constrain federal immigration enforcement.

In remarks Thursday, Senate Majority Leader John Thune said Democrats’ demands for new restrictions on immigration enforcement officers are “unrealistic,” and warned that the Department of Homeland Security will shut down next week if Democrats and Republicans do not work with the White House. Thune said, “This is not a blank check situation where Republicans just do agree to a list of Democrat demands,” adding, “The only way to get reforms to ICE is to agree to a bill.” He also said, “we aren’t anywhere close to having any sort of an agreement.”

Democrats, however, say they will not vote for the DHS spending bill when funding runs out unless there are “dramatic changes” at U.S. Immigration and Customs Enforcement and other federal law enforcement agencies following the fatal shootings of two protesters in Minneapolis last month. The Democratic leaders, Sen. Chuck Schumer and Rep. Hakeem Jeffries, released an expanded list of 10 detailed proposals on Wednesday night aimed at restraining President Donald Trump’s immigration enforcement campaign.

Schumer said he was “astounded to hear” Republicans describe the proposals as political or unworkable, arguing that “It’s about people’s basic rights, it’s about people’s safety,” and telling Republicans that if they object to the ideas, “they need to explain why.” The proposal list includes requirements Democrats say would apply to immigration officers’ use of force, identification, and safeguards around detention operations, as well as rules intended to prevent racial profiling.

Among the Democrats’ demands are a requirement for judicial warrants, better identification of DHS officers, and changes to use-of-force standards. Democrats also called for an end to racial profiling, saying DHS officers should be prohibited from stopping, questioning or searching people “based on an individual’s presence at certain locations, their job, their spoken language and accent or their race and ethnicity.” The list also calls for officers conducting immigration enforcement to take off masks, show identification, and follow standardized uniforms and equipment comparable to other federal law enforcement agencies.

Schumer and Jeffries said the proposals are connected to the scrutiny facing immigration enforcement actions after the Jan. 24 shootings in Minneapolis. Congress began reshaping the DHS spending measure after Trump agreed to a Democratic request to separate the DHS bill from a larger spending package and extend the measure at current levels for two weeks while negotiations proceed. The AP report also links the renewed focus on the talks to the death of ICU nurse Alex Pretti, who was shot and killed by a U.S. Border Patrol officer in Minneapolis on Jan. 24, and notes that some Republicans agreed new restrictions were necessary.

Republicans in the negotiations have pushed back on the Democrats’ approach. Wyoming Sen. John Barrasso described the demands as “radical and extreme” and a “far-left wish list,” while Sen. Katie Britt, who is helping lead talks, said the list is “a ridiculous Christmas list of demands” and warned that time is running out before the deadline. Britt urged Democrats to talk with the White House and said, “We only have one week left.”

With the talks moving toward a Feb. 14 point when lawmakers say a shutdown is increasingly likely, some lawmakers have been floating ideas to reduce shutdown pain by separating parts of the DHS portfolio. Republican Sen. Thom Tillis suggested lawmakers could take certain agencies within DHS—such as Coast Guard operations, airport operations under TSA, and disaster assistance from FEMA—off the table. “Why not take that off the table?” Tillis said.

Democrats and Thune, though, have expressed concern that splitting the bill could undercut immigration enforcement funding itself. The AP report says Thune rejected the idea of removing ICE from the broader DHS appropriations package, saying that splitting apart the DHS bill to single out ICE would “defund law enforcement.” Thune also warned that if DHS shuts down, there is “a very good chance we could see more travel problems” like those that occurred during a 43-day government closure last year.

At the same time, the AP report says some Republicans have demands of their own, including legislation requiring proof of citizenship before Americans register to vote and restrictions on cities they say do not do enough to crack down on illegal immigration. Sen. Chris Murphy, a Connecticut Democrat, said the obligation to avoid a shutdown falls on Republicans because they control negotiations, adding, “The American people want this abuse to stop.”

Thune said it remains unclear whether Democrats and the White House are actually negotiating behind the scenes and whether Democrats would be willing to back down from any of their demands.