Rep. Norm Dicks, D-Wash., who last week was set to support the GOP continuing resolution, said he expects most other House Democrats to do the same.
House Minority Whip Steny Hoyer, D-Md., has also sent out a "Whip's Alert" to rank-and-file members urging that they vote "no" on the Republican bill.
The prospect of widespread House Democratic opposition could complicate final passage in both the House and the Seante later this week of the measure needed to extend funding and keep government operations running beyond the Sept. 30 end of the current fiscal year.
The GOP-led House has scheduled a Wednesday-evening vote on the bill, which includes $3.65 billion to replenish a Federal Emergency Management Agency disaster-aid fund.
"I will vote no," said Dicks.
Hoyer's alert reads, "Despite the practice of the previous administration declaring disaster funding as emergency spending and not offsetting emergency spending, this bill would offset the $1 billion in fiscal 2011 disaster relief funding using a program that is a proven job-creator."
The alert adds, "This is a dangerous cut that will affect American jobs and another example of the Republicans' inability to compromise, and the continuation of their no-jobs agenda."
At issue is whether House Republicans can get enough votes to back a version of the bill if it is returned to them with the changes that Senate Majority Leader Harry Reid, D-Nev., is considering. Reid has called the disaster-aid funding in the House bill inadequate; he said he will offer an amendment to it attaching $6.9 billion in FEMA funding that the Senate approved last week. The Senate bill does not offset the funding. In explaining his change of heart as he left a House Democratic Caucus meeting, Dicks said that he also had always had concerns about the bill's $1.5 billion cut in the Republican bill to funding for the Energy Department's Advanced Technology Vehicle Manufacturing Program -- as an offset -- being counterproductive for the economy.
"This automobile and parts program has created jobs, and we have a huge number of members in our caucus … concerned that this really hurts that program," said Dicks.
"On reflection, and after a lot of members have come to us, the leaders have decided that … because the source of the funding is a job-creation program, we're going to vote no," he said.
Dicks added, "We have enough time to have a bit of discussion about this."
The Washington state Democrat had suggested quite the opposite last week, saying then that he would support the bill despite his concerns. "The last thing we need, with a fragile economy and regions reeling from natural disasters, is another partisan political fight in Congress," Dicks said at the time.
"The American public wants us to act quickly. We should pass this CR and work together to enact fiscal 2012 appropriations that promote economic growth and encourage job creation," he had said.