Key Republican senators head to the White House Thursday afternoon to meet with President Donald Trump, hoping to resolve a border brawl that could hold up a year-end spending package and lead to a partial government shutdown.

The White House session could make clear whether Trump is prepared to give any ground in his request for a $5 billion down payment on a southern border wall — or whether he’s prepared to trigger a shutdown if he doesn’t get his way. Senate appropriators have offered only $1.6 billion in their bipartisan version of a Homeland Security spending bill.

“I think what we might figure out is what’s doable, what can we do to move the process, what can we do to satisfy him enough to move the process,” said Senate Appropriations Chairman Richard C. Shelby, R-Ala, who plans to attend the meeting with Senate Majority Leader Mitch McConnell, R-Ky. “The meeting with the president, I would think, the impetus would be how do we resolve the wall.”

Democratic leaders, who aides said won’t attend, have shown no signs of bending toward Trump’s request, particularly after winning a House majority and largely holding their own in the Senate after bruising midterm elections.

“The Democrats and Republicans came to a $1.6 billion agreement,” Senate Minority Leader Charles E. Schumer, D-N.Y., told reporters Wednesday. “We believe Democrats and Republicans should stick with their agreement and not let President Trump interfere. Every time he interferes, it gets bollixed up.”