Democrats say the Louisiana money shouldn’t be included unless more than $200 million is added for Flint, Michigan, where lead has contaminated the water supply. Democrats have been pushing the GOP-led House and Senate for months to allocate funds for Flint, to no avail.

“People of Flint are told no, and then all of a sudden there is help for Louisiana,” Sen. Debbie Stabenow, D-Mich., argued on the Senate floor Tuesday.

The fight between the red and blue state federal aid was the main reason lawmakers voted to block the spending bill from advancing on Tuesday, and it left Congress with no agreement on a federal funding bill with just three days left before the fiscal year ends. In addition to funding the government through December 9, the measure also includes critical money for the federal government to battle the Zika virus, a mosquito-transmitted disease which is spreading in southern states.

Senate Majority Leader Mitch McConnell, R-Ky., said ultimately if Democrats are going to insist on parity in federal aid, he’ll strip out the flood money altogether, from both states.

“What I indicated a willingness to do is think about what has been the Democratic position, which was if there was no Flint, there’d be no flood,” McConnell said Tuesday.

Senate Republican leaders said they are wary of adding Flint spending to the measure because House Republicans don’t want it there, which might make it more difficult for the spending measure to clear the House.

But a solution could be at hand.

The House is expected to vote this week on a water resources bill that would allow an amendment to add Flint money. If it passes, Senate Democrats said they may feel more assured that Flint will get federal dollars, even if it is not included in the stopgap spending bill.

Sen. Barbara Boxer, D-Calif., the ranking member on the Senate Environment and Public Works panel, called on House Republicans to provide “an ironclad commitment” that the money would be included in the House water resources bill. A Senate-passed version already includes the $220 million for Flint.

“Trust but verify,” Boxer said. “All they have to do is allow a vote to cover Flint.”

Democrats are clearly wary of a trick. Minority Leader Harry Reid, D-Nev., said Democrats “have been jerked around so many times” by Republicans over providing federal funding for Flint, he no longer trusts them.

Republicans have given Democrats reason to be cautious. Many House Republicans, including Speaker Paul Ryan, R-Wis., say the Flint water crisis should not qualify for emergency federal spending because it is not a natural disaster, and should be handled by the local government.

Ryan’s middle ground was to allow a debate on adding to the water resources bill, and some Republicans said they back putting the money in that measure.

Stabenow and other Democrats said they would ultimately prefer the money to be added into the stopgap spending bill, which is a must-pass measure that would be immediately signed into law. Stabenow noted that unlike the flood aid, which adds to the deficit, the Flint money is fully offset by scaling back other federal programs, an approach Democrats don’t like.

Still, Stabenow said Democrats are eager to avoid McConnell’s threat to strip out money for both floods and Flint.

“It would be a tragedy and outrageous way to make decisions if the answer to all of this is OK, we won’t help Louisiana either,” Stabenow said. “That is not what we are suggesting.”