Senate Democrats on Wednesday laid out demands for the Department of Homeland Security, including an enforceable code of conduct for federal agents conducting immigration arrests and requirements that officers show identification, as lawmakers warned that funding for DHS and a swath of other agencies would expire Saturday. Democrats said they would block a spending bill unless their demands are met, setting up uncertainty over whether President Donald Trump and Republicans would negotiate ahead of the deadline.

The standoff is centered on U.S. Immigration and Customs Enforcement, which Democratic leaders said must be “reined in and overhauled.” Senate Democratic leader Chuck Schumer said Wednesday that legislation won’t pass until ICE is “reined in and overhauled,” arguing that the American public supports law enforcement and border security but does not support ICE “terrorizing our streets and killing American citizens.” He also told reporters that Democrats want changes that would bring ICE arrest and enforcement practices closer to standards followed by local policing.

Minnesota Sen. Tina Smith said after a lunch meeting Wednesday that there was “a lot of ‘unanimity and shared purpose’ within the Democratic caucus.” She described the package of demands in terms of accountability and rules of operation, saying: “Boil it all down, what we are talking about is that these lawless ICE agents should be following the same rules that your local police department does,” adding, “There has to be accountability.”

Schumer said Democrats are asking the White House to “end roving patrols” in cities and to coordinate with local law enforcement on immigration arrests, including tighter rules for warrants. He also said the lawmakers want an enforceable code of conduct so that agents are held accountable when they violate rules, describing the changes as involving “masks off, body cameras on” and proper identification—practices he said are common in other law enforcement agencies.

Democrats framed their demands as a set of “commonsense reforms” and said the burden is on Republicans to accept them. Schumer said he has asked Republicans to separate the Homeland Security bill from other funding measures to avoid a broader shutdown, even though the House has already passed the remaining funding bills as a package, sending them to the Senate for consideration together.

The legislative timetable and the package structure could limit Democrats’ leverage. Democrats’ ability to pull out the homeland security portion is constrained, the report said, because Republicans would need consent from all 100 senators to break the package apart, or else use a sequence of votes that would extend beyond a Friday deadline. At the same time, House Republicans have signaled they would not accept changes to what the House passed.

A letter to Trump from the conservative House Freedom Caucus, written Tuesday, said the package would not return to the House without funding for the Department of Homeland Security, according to the report. Republicans who spoke Wednesday suggested they might be willing to proceed with separating the bills for further debate, but several indicated they oppose key ICE-related requirements.

Sen. Thom Tillis said he was “OK with separating the bills” but opposed Democrats’ proposal to require immigration enforcement officers to unmask and show their faces. Tillis said he disagreed with the masks requirement because, as he put it, “You know, there’s a lot of vicious people out there, and they’ll take a picture of your face, and the next thing you know, your children or your wife or your husband are being threatened at home. And that’s just the reality of the world that we’re in.”

Sen. John Cornyn said the deaths in the dispute “over the weekend is a tragedy,” but he argued Democrats shouldn’t respond by pressing toward a shutdown described as a “political stunt.” In contrast, Democrats said they would not back down, with Sen. Richard Blumenthal calling it “truly a moral moment” and adding: “I think we need to take a stand.”

Lawmakers also pointed to recent unrest and the political context around the funding fight. The report said the country has been reacting to the deaths of two protesters in Minneapolis at the hands of federal agents, identifying the protesters as Alex Pretti and Renee Good, and it said Democrats have pledged to use the DHS funding negotiations to push for changes. It also said the renewed shutdown threat echoes a dispute two months earlier in which Democrats blocked a spending bill over expiring federal health care subsidies, closing the government for 43 days before a deal was reached after a small group of moderate Democrats broke away; this time, the report said Democrats were more united.