WASHINGTON — Senate Majority Leader John Thune said Thursday that demands made by Democrats for new restrictions on federal immigration officers are “unrealistic” and warned that the Department of Homeland Security will shut down next week if they do not work with Republicans and the White House.

Democrats say they will not vote for a DHS spending bill when funding runs out unless there are changes at U.S. Immigration and Customs Enforcement and other federal law enforcement agencies in the wake of 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 for restraining President Donald Trump’s aggressive campaign of immigration enforcement. Among the demands are a requirement for judicial warrants, better identification of DHS officers, new use of force standards and a stop to racial profiling.

Thune, R-S.D., said most of the demands are “very unrealistic and unserious” and he called on Democrats to negotiate.

“This is not a blank check situation where Republicans just do agree to a list of Democrat demands,” he said. “The only way to get reforms to ICE is to agree to a bill.”

Schumer, D-N.Y., said he is “astounded to hear” Republicans say his party’s proposals were political or unworkable.

“It’s about people’s basic rights, it’s about people’s safety,” Schumer said. If Republicans do not like the ideas, he said, “they need to explain why.”

As the two parties traded blame, a DHS shutdown appeared increasingly likely, starting Feb. 14. As of now, Thune said, “we aren’t anywhere close to having any sort of an agreement.”

In addition to ICE and U.S. Customs and Border Protection, the homeland security bill includes funding for the Federal Emergency Management Agency and the Transportation Security Administration. If DHS shuts down, Thune said, “there’s a very good chance we could see more travel problems” similar to the 43-day government closure last year.

Schumer and Jeffries, D-N.Y., have made several demands, including no masks for officers, judicial warrants and better federal coordination with local authorities. The list they released Wednesday added several new items, including a stricter use of force policy, legal safeguards at detention centers and a prohibition on tracking protesters with body-worn cameras.

Democrats say Congress should end indiscriminate arrests, “improve warrant procedures and standards,” ensure the law is clear that officers cannot enter private property without a judicial warrant and require that before a person can be detained, it’s verified that the person is not a U.S. citizen.

They also want 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.”

For officers conducting immigration enforcement, Democrats say that in addition to officers taking off their masks and showing identification, DHS should regulate and standardize uniforms and equipment to bring them in line with other law enforcement agencies.

Schumer called it a “gut check moment for Congress” as the immigration enforcement operations have rocked Minneapolis and other U.S. cities. But Republicans were dismissive.