A growing number of lawmakers from the Senate's progressive wing are warning they will oppose a December government funding bill without a deal on a key Obama-era immigration program.

Sen. Bernie Sanders Bernie SandersKenosha will be a good bellwether in 2020 Biden's fiscal program: What is the likely market impact? McConnell accuses Democrats of sowing division by 'downplaying progress' on election security MORE (I-Vt.) and Cory Booker Cory Anthony BookerBipartisan praise pours in after Ginsburg's death DHS opens probe into allegations at Georgia ICE facility Democratic lawmakers call for an investigation into allegations of medical neglect at Georgia ICE facility MORE (D-N.J.) are the latest senators to link the two issues, foreshadowing the likely end-of-the-year showdown lawmakers will face.

"Trump must make good on his promise to sign a bill protecting Dreamers. I won't vote for any spending bill without a permanent DACA fix," Sanders said in a tweet on Friday.

ADVERTISEMENT

A spokeswoman for Booker said the New Jersey Democrat would also oppose the funding bill if it doesn't include a fix for the Obama-era Deferred Action for Childhood Arrivals (DACA) program.

Booker said on Friday that Trump is throwing "the lives and futures of hundreds of thousands of dreamers into chaos and uncertainty."

"I want solutions to protect these kids, and won’t vote for a spending bill that doesn’t include one. It’s an issue of basic decency and morality," he said.

Trump announced in September that he would phase out the program, which allows undocumented immigrants brought into the country as children — commonly referred to as "Dreamers" — to work and go to school without the fear of deportation.

Unless Congress passes legislation by early March, the hundreds of thousands of DACA recipients would be at risk of being deported.

Sen. Kamala Harris Kamala HarrisThe Hill's Campaign Report: Trump and Biden vie for Minnesota | Early voting begins in four states | Blue state GOP governors back Susan Collins Kamala Harris: Black Americans have been 'disproportionately harmed' by Trump Biden town hall draws 3.3 million viewers for CNN MORE (D-Calif.) became the first Senate Democrat to warn she wouldn't support a December government funding bill without an agreement providing protections for the young immigrants.

“I will not vote for an end-of-year spending bill until we are clear about what we are going to do to protect and take care of our DACA young people in this country,” she said during a rally on Capitol Hill last week.

On Thursday, Trump and Senate Republicans agreed during a closed-door meeting to oppose including an immigration deal in the December funding bill.

Hours after the meeting, Sen. Elizabeth Warren Elizabeth WarrenBiden's fiscal program: What is the likely market impact? Warren, Schumer introduce plan for next president to cancel ,000 in student debt The Hill's 12:30 Report - Presented by Facebook - Don't expect a government check anytime soon MORE (D-Mass.) followed Harris's lead by drawing a similar red line.

"Do your job, Mr. President. Stop playing politics [and] fix this," she said in a tweet, asserting that Trump is "willing to abandon Dreamers after all."

The Democratic senators, who are both considered possible contenders for the party's 2020 White House nomination, don't have the ability to sink the government funding bill on their own.

But Republicans will need to win over at least eight Democrats if they want to be able to overcome the Senate's 60-vote procedural hurdle.

Lawmakers are facing a Dec. 8 deadline to reach a funding deal and avoid a government shutdown.