The coming days represent a crucial stage in the negotiations if both sides are to avert a government shutdown. Last week, Vice President Joe Biden played a role in keeping the talks on track after a session broke up in acrimony. But he has been trying to keep a low profile, said one Democrat familiar with the negotiations, out of concern that Republicans would rather not be seen as making a deal with the White House.

“I think there’s a certain reluctance to negotiate with the White House directly,” the Democrat said. “Some of that is, I think, institutional. Some of it is political.”

Another stumbling block: conservative-backed amendments contained in the House bill that would cut off funding for the health-care law and other administration priorities.