GOP civil war erupts over Trump's latest agenda push as key Republicans threaten to sink megabill

House GOP leaders are scrambling to approve a sprawling budget reconciliation package packed with defense and election integrity priorities, but Republican lawmakers in both chambers are pouring cold water on the process.

The intraparty skepticism, including concerns over the lack of spending offsets, is throwing the ambitious timeline into doubt. And the move to attach the SAVE America Act to the process has already turned off some of its GOP opponents.

"If we keep on layering layers of complexity, like another bogus attempt at the SAVE Act, then we're never gonna get it done," Sen. Thom Tillis, R-N.C., said.

When asked if it included the legislation if he would vote "no," Tillis said, "Absolutely."

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"And I'll slow other things down, too," the retiring senator said. "It's a waste of time. It's an exercise of futility, and those are the only positive things I can think of to say about it."

Still, House Speaker Mike Johnson, R-La., has voiced confidence that both chambers can approve a budget blueprint — the first step in the complex reconciliation process — before lawmakers leave Washington for the August recess. The House Budget Committee advanced the budget plan Thursday, teeing up floor consideration as soon as next week.

But across the building, Senate Majority Leader John Thune, R-S.D., said that Johnson’s assurance was, "news to me."

Thune acknowledged the desire to push both defense funding and the SAVE America Act through the party line process, but warned of consequences that could appear along the way.

"Again, the question is $60 billion worth the risk of putting something like that on the floor, and all the other harm that could potentially come from that," Thune said.

The truncated timeline comes as the House is expected to leave for August recess by the end of next week, while the Senate will depart Washington, D.C., the first week of August. Some in the upper chamber argue that lawmakers shouldn’t go home if their work isn’t done.

"If we don’t get this done, we’re gonna to — I think we’re gonna have to stay," Sen. Rick Scott, R-Fla., told Fox News Digital.

The Trump administration is also providing backup to reconciliation 3.0’s proponents.

The White House sent an internal memo to Hill offices Thursday expressing support for House Republicans’ $95 billion budget framework, which would allocate $73 billion in defense and intelligence funding among other provisions in a forthcoming bill.

"Congress must pass this budget resolution—without modification—immediately," the document said in part.

Several Republicans told Fox News Digital they believe that will be a tough sell.

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California Rep. Kevin Kiley, an independent who caucuses with Republicans, told Fox News Digital he is "skeptical" about a third reconciliation bill.

Kiley said he is concerned that the $73 billion in defense funding could be spent with little congressional oversight.

"This is really our opportunity here for the House to assert itself when it comes to directing the resolution of this conflict on acceptable terms," the California lawmaker said, referring to the war with Iran.

Kiley also said he opposes the budget reconciliation process because it intentionally cuts out Democrats from negotiations and said lawmakers should be relying on the normal appropriations process.

He voted against Republicans’ $72 billion immigration enforcement funding package earlier this year in part because the measure lacked buy-in from Democrats.

Fiscal hawks in both chambers have griped that the budget blueprint does not direct Congress to cut any spending — a move that would almost certainly increase budget deficits and contribute to the national debt.

"I think you got to pay for it," Rep. Eric Burlison, R-Mo., told reporters Thursday.

The lack of spending offsets was met with a cold reception in the upper chamber as well.

"Our national debt is a runaway train. The next reconciliation bill should be fully paid for," Sen. Bill Cassidy, R-La., who lost re-election to a Trump-backed challenger, wrote on social media Thursday.

Burlison also said he does not support Republicans' strategy of using a $10 billion funding pool to distribute grants to incentivize states to implement elements of the SAVE America Act, including citizenship verification and voter ID requirements.

He added that he could be convinced to vote for the budget framework if GOP leaders are able to force Democratic-led states to implement those provisions.

"To me, it's not worth it if it's weak language," he continued. "You have huge incentives in Obamacare, and you still have 11 states that rejected hundreds of millions of dollars to expand Medicaid. So it's nothing for states … if we're going to just throw a few million bucks their way."

Complicating matters is whether Trump would even sign a reconciliation bill that didn’t include the entirety of the SAVE America Act, given how much he has pushed Republicans to pass the whole thing.

"I know, I know," Thune told Fox News Digital. "That's a good question. If you get the answer, let me know."