With U.S. government funding due to expire at midnight on Tuesday, Republicans and Democrats in Congress are showing no signs they will agree to a temporary spending fix that would avert a shutdown.

President Donald Trump will convene a meeting with congressional leaders at the White House on Monday in a last-ditch attempt to end the standoff. But Democrats have signaled they are not willing to simply sign off on the short-term funding plan Republicans support without some accommodations.

If Congress does not act, thousands of federal government workers could be furloughed, from NASA to the national parks, and a wide range of services would be disrupted. Federal courts might have to close and grants for small businesses could be delayed.

This is a fight over more than temporary funding, however. It is the continuation of a battle that has been brewing since Trump took office in January and refused to spend billions of dollars that Congress had already approved.

Democrats aim to use the threat of a shutdown to restore some of that funding and shore up healthcare subsidies due to expire at the end of the year.

At stake is $1.7 trillion in "discretionary" spending that funds agency operations, which will lapse at the end of the fiscal year on Tuesday if Congress does not extend it.

That amounts to roughly one-quarter of the government's total $7 trillion budget, with much of the remainder going to health and retirement programs and interest payments on the $37.5 trillion debt.

The spotlight will be on Trump, a Republican who has blamed Democrats for the impasse, and Senate Democrat Leader Chuck Schumer, who will have to keep his rank-and-file in line in order to attain his party's goals.

The Republican-controlled House of Representatives narrowly passed a bill on Sept. 19 to keep government agencies funded through Nov. 21. The Senate, where 60 votes were required to approve the measure, promptly defeated it.

There have been 14 partial government shutdowns since 1981, most lasting just a few days. The most recent was also the longest, lasting 35 days in 2018 and 2019 due to a dispute over immigration.

This time healthcare is at issue. Roughly 24 million Americans who get coverage through the Affordable Care Act will see their costs rise if Congress does not extend temporary tax breaks that were passed in 2021.

Schumer on Sunday said there will be "huge pressure" on Republicans to agree to talks to restore healthcare cuts, which he said threaten to close rural hospitals and dramatically hike insurance premiums.

"We don't want a shutdown," he said on NBC's "Meet the Press." "We hope that they sit down and have a serious negotiation with us."

Senate Republican Leader John Thune has left the door open to eventually dealing with the healthcare problem, but says Congress must first pass a temporary spending bill to avert a shutdown.

"You can't do this by Tuesday, and you can't do it while you're holding the American people hostage with a government shutdown," he said on "Meet the Press."

Some Democrat aides in Congress have suggested lawmakers could back a short funding bill if Republicans agreed to hold votes within the next several weeks on the Affordable Care Act tax credit extension.

But House Democrat Leader Hakeem Jeffries dismissed that idea on Friday, saying Republicans cannot be trusted. "Now, we're supposed to believe, with a wink and a nod, that Republican leaders are actually interested in dealing with the Affordable Care Act issue?" he said.

Democrats desperately want to energize their voting base ahead of the 2026 midterm elections, when control of Congress will be at stake, and lawmakers from the party's center as well as its left have lined up behind the effort to boost healthcare spending.

Moderate Democrat Rep. Hillary Scholten said her constituents do not want her to support any spending bill that does not shore up healthcare, pointing in particular to children's cancer research.

But she also said that a shutdown could hurt her Michigan district.

"We've got the U.S. Coast Guard, a huge installation," she said in an interview. "They don't get paid when the government gets shut down."

Democrat Rep. Joe Courtney of Connecticut said he worried about medical research cuts at Yale University and the University of Connecticut. "It's devastating to patients who are in clinical trials," he said.

The strategy comes with risks.

Democrat aides, speaking on condition of anonymity, expressed concerns that a shutdown could create a public backlash if Democrats do not effectively argue their case and instead come off sounding as just being opposed to whatever Trump wants - a stance Republicans like Thune have derided as "Trump Derangement Syndrome."

"They're playing with fire, and they know it," Thune said on Sunday.