Congress is still at odds over border security funding and leaders are now weighing fallback plans should no agreement be reached when government funding runs out on Dec. 7.

Congressional leaders are increasingly frustrated that a partial government shutdown is potentially two weeks away, particularly because both parties have already largely agreed to spending levels for 2019. In late September Congress passed a 2019 appropriations package that includes big spending increases for the Pentagon as well as for the Labor, Education and Health and Human Services departments. However, funding for Homeland Security and the wall that President Trump wants built at the U.S.-Mexico border is still not set.

President Trump has not ruled out a shutdown if he doesn’t get at least $5 billion for the wall. Senate appropriators had allocated only about $1.6 billion for the wall in their Homeland Security bill, and Senate Democrats have no appetite for increasing that amount. Senate Minority Leader Chuck Schumer (D-NY) has urged Trump to stay out of the negotiations.

The Senate appropriations process has been running smoothly up to this point, with both sides noting the bipartisan work taking place. That tone has changed this week.

“I don’t want to screw with those deadlines,” Senate Homeland Security Chairman Ron Johnson (R-WI) said on Tuesday. “I don’t want to engage in shutdown politics. Let’s fund the federal government and move on. I wish Democrats would cooperate. They all said they want to secure the border, so okay, it’s going to require better barriers.”

“If [$5 billion for the border wall] gets in the mix, there has to be something in return for that,” Rep. Gerry Connolly (D-VA) told POLITICO. “I myself have a pretty hard position that Democrats should not even be engaged in discussions about that because [Trump] made it very clear that Mexico was going to pay for that wall.”

If compromise can’t be reached, it’s possible Congress could pass a continuing resolution to fund some agencies at 2018 levels through next September.