House Republicans are expected to introduce a short-term spending bill today (December 7) that would keep the federal government running until December 22, but top Democrats say they won’t vote for the year-end funding bill unless it contains provisions that protect young immigrants, called Dreamers, from the threat of deportation.

Senators Kamala Harris (D-Calif.), Elizabeth Warren (D-Mass.), Cory Booker (D-N.J.) and Bernie Sanders (I-Vt.) say they won’t vote for any measure that doesn’t shelter Deferred Action for Childhood Arrivals (DACA) recipients, the nearly 800,000 young immigrants who were brought to the U.S. as children.

Said Kamala Harris, according to The Hill:

I have been clear. Any bill that funds the government must also include a fix for the young immigrants.

House Minority Leader Nancy Pelosi (D-Calif.) and Senate Minority Leader Chuck Schumer (D-N.Y.) are expected to meet President Donald Trump at the White House today, where they will attempt to resolve major differences, including immigration, before reaching a deal on the funding bill. Trump has not budged from his demand for border wall funding and a hard-line immigration stance.

Referring to a potential government shutdown, Trump said, “it could happen” during his Wednesday cabinet meeting:

Democrats are really looking at something that is very dangerous for our country. They are looking at shutting down. They want to have illegal immigrants in many cases, people that we don’t want in our country, they want to have illegal immigrants pouring into our country.

Democrats are divided on the year-end immigration fix. Some Democratic lawmakers facing election in states that Trump carried in 2016 do not want the government shutdown to hinge on the immigration issue, according to The Hill.

Meanwhile, on Tuesday (December 5), 34 Republicans sent a letter to House Speaker Paul Ryan (R-Wis.) outlining support for a legislative solution for Dreamers. The letter says, in part: 

While we firmly believe Congress must work to address other issues within our broken immigration system, it is imperative that Republicans and Democrats come together to solve this problem now and not wait until next year.

Senate Republicans introduced a DACA measure on December 5 that extends Dreamers’ protection from deportation for three years. But the bill, called the SECURE Act, was panned by Senator Dick Durbin (D-Ill.) for not providing young immigrants a path toward citizenship and targeting sanctuary cities that limit cooperation with federal immigration enforcement.

Earlier this week, Durbin said he was “not confident” that Congress would approve the bipartisan Dream Act that he co-sponsored, which would help Dreamers obtain citizenship.