Republicans are going down to the wire as they try to find a way out of their showdown with President Trump over his national emergency to build a wall on the Mexican border.

Republicans have just days to find a more palatable solution than the House-passed resolution blocking Trump's actions, which is expected to come up for a vote by Friday.

They are looking for ways that Trump could win more wall funding without using the emergency declaration, a controversial move that has caused angst on Capitol Hill.

“I think we’re universally for what the president wants to do, but there’s significant concern about using the emergency in this new way that sets a precedent likely in court that future presidents could use,” said Sen. Roy Blunt (R-Mo.), a member of GOP leadership.

Without an off ramp, the resolution of disapproval has enough votes to pass the Senate, and as many as 15 Republicans could vote for it. That would be an embarrassingly high number for the White House, even if a Trump veto cannot be overridden.

Republicans have yet to find a plan that unites the caucus and passes procedural muster with the parliamentarian.

“My sense was we were kind of down to Plan Z. Started with Plan A and found that none of those worked,” Blunt said.

Sen. John Thune (R-S.D.), the No. 2 Senate Republican, said “the marketplace of ideas is percolating,” while Sen. John Cornyn (R-Texas) told CNN that there were “great ideas but no conclusions.”

The talks have ranged from amending the resolution to passing a separate standalone measure. Leadership staffers have been deputized to scour the chamber’s rules for help.