WASHINGTON (AP) — Democrats opened a last-minute push Tuesday for new talks on must-do legislation to prevent the government from shutting down this weekend, fight the Zika virus and help flood-ravaged Louisiana rebuild.

The aim is to see if Republicans will relent and add money to help Flint, Michigan, with its water crisis — and get Capitol Hill off a collision course that could lead to a government shutdown this weekend.

Without progress on the Flint water issue, Democrats are poised to block the stopgap funding bill Tuesday afternoon, a step that could increase the chances of a shutdown at midnight Friday. They are pressing to add a bipartisan, Senate-passed measure to provide $220 million to help Flint and other communities with lead-poisoned water replace pipes and take other steps.

Democrats say it's unfair that the water crisis in Flint has gone on for a year with no assistance, while Louisiana is getting $500 million for floods that occurred just last month as part of the 10-week stopgap bill, called a "CR" (for "continuing resolution") in Washington code.

"Democrats have been clear that Congress should not leave Flint and other lead-tainted communities out of any (stopgap spending) negotiation that includes emergency disaster funding," said Senate Minority Leader Harry Reid, D-Nev., and other top Democrats in a Tuesday morning letter to McConnell. "Our request is simple: include both bipartisan disaster relief packages for consideration in the CR. We urge you to include bipartisan Flint legislation in the CR."

If Democrats filibuster the stopgap legislation Tuesday, Senate Majority Leader Mitch McConnell, R-Ky., has just a handful of options, one of which would be to strip $500 million in flood aid for Louisiana and other states from the bill.

"Is their solution now to remove help for flood victims?" McConnell asked in a Monday floor speech. "If their solution is to remove help for flood victims, they should say so."

Republicans say the Flint issue will be handled in a separate measure to authorize water development projects. That measure — without Flint money — is set for a House floor debate Tuesday, but Republicans are telegraphing it will be included in any final measure handled in a post-election session.

"We are going to deal with Flint," said House Majority Leader Kevin McCarthy, R-Calif.