A partisan skirmish erupted over a Pentagon spending bill Wednesday, bringing to an abrupt halt the wave of cross-party goodwill that helped congressional leaders shepherd a bipartisan budget agreement to passage last week.

Senate Majority Leader Mitch McConnell on Tuesday teed up a Thursday vote on breaking a filibuster on proceeding to the fiscal 2016 Defense spending bill (HR 2685), seeking to bring the sprawling title up for consideration in the Senate for the third time this year. And for the third time, the Kentucky Republican likely will be rebuffed by Democrats hungry for a larger spending deal.

Should Democrats help McConnell secure 60 votes to move forward on the bill, the Republican leader would introduce a substitute amendment that would include the Senate Appropriations-reported version of the legislation (S 1558). It would be amended to reflect the defense spending limits in the bipartisan budget accord (HR 1314) signed into law by President Barack Obama Monday.

But the gambit is not likely to pass muster with angered Senate Democrats, aides and lawmakers said Wednesday. They are deeply wary that Republicans will want to pass a full, line-by-line spending bill only for the Pentagon and leave the other 11 appropriations titles in the dust, funded on autopilot under year-long continuing resolutions.

“Right now, we do not trust this process,” said Barbara A. Mikulski of Maryland, the top Democrat on Senate Appropriations.

Mikulski said she plans to vote against the procedural motion to begin debate until she receives assurances that all 12 appropriations titles will be taken care of under full spending plans for the remaining 10 months of the fiscal year.

“All we need is to have a publicly declared declaration that we’re going to do all bills in a comprehensive appropriations package,” she said.

McConnell Speaks Out

But McConnell told CQ Roll Call in an exclusive interview that Republicans don’t support further stopgap funding for any department or agency.

“I guess they’re suspicious that somehow we’ll end up with a CR. That makes no sense. We’re the majority,” McConnell said. “Why would we not want to pass the appropriations bills that we wrote?”

McConnell said he had already told Mikulski, Minority Leader Harry Reid of Nevada and other Democrats that he wanted to see the appropriations process completed.

“We have no interest in doing a continuing resolution,” McConnell said. “After all, we’re in the majority. We wrote the bills.”

“They’re making up something that would not be in [the GOP majority’s] best interests, to wipe out all the work that we’ve done on the appropriations committee by passing a CR,” McConnell said.

‘Spirit’ of the Budget Deal

Wednesday’s back-and-forth could make it harder for bipartisan negotiators to find consensus on spending and policy provisions that would form the flesh of a wrap-up spending agreement for the year. The talks are formally kicking off this week.

Some Senate Democrats implied that McConnell was breaking with the spirit of the two-year budget accord.

The parties agreed “to keep the government open through an omnibus package,” said Chris Coons of Delaware, a Democratic appropriator.

“I think it’s an unfortunate, uncalled-for procedural trick to try and move the one big, important, vital appropriations piece and then move to everything nondefense,” Coons said Wednesday.

Separately, several senators said McConnell could move to bring up a standalone version of the fiscal 2016 Military Construction-VA appropriations bill (HR 2029) next. Such a gambit would require Democrats to block funding for veterans health care and military bases the same week as Veterans Day on Nov. 11. Aides to McConnell said no announcements have been made on the schedule.

Meanwhile, the House is set to pass a new defense authorization bill (S 1356) Thursday under suspension of the rules that cuts $5 billion from the initially-passed measure in order to confirm to the two-year budget framework.

Five-Year-Old Battle

Democrats are perennially cagey about moving Defense appropriations as a standalone bill, and they point to the fiscal 2011 appropriations cycle as an example of how Republicans operate when it comes to funding defense versus domestic priorities.

Twelve appropriations bills were held back in late 2010, after Republicans captured control of the House in a landmark midterm election. Democratic leaders in both chambers were unable to move a 12-bill omnibus and instead advanced a short-term continuing resolution into the new Congress.

The Democrats were at loggerheads with the emboldened new GOP majority on policy riders and spending levels for months. After a series of disruptive short-term stopgaps, a wrap-up fiscal 2011 agreement (PL 112-10) was not passed until April and included a full spending plan only for the Pentagon. The rest of the government was put on autopilot through the remaining five-and-a-half months of that year.

As a result, Democrats typically try to hold back the military spending measure until a wrap-up omnibus deal can be reached so it can sweeten the deal for Republicans to support some of the other more contentious domestic appropriations bills.

Democratic Filibusters

The Senate previously took up the Defense appropriations measure (HR 2685) in June and September. Both times, Democrats blocked consideration of the bill while they held out for a new budget deal to raise discretionary spending caps. The margins were 50-45 and 54-42, both shy of the 60-vote threshold to proceed.

Republicans have framed those Democratic filibusters as the party not being supportive of the military.

That rhetoric continued Wednesday. In a speech on the Senate floor, McConnell said it’s time to take up individual appropriations bills after the two-year budget agreement was signed into law.

“I think it’s time to finally support the men and women who volunteer to protect us,” McConnell said.

“The last excuse not to do so — the setting of a topline budget number — has been cleared away. There’s no reason our colleagues shouldn’t join us in moving forward now.”

He suggested Democrats were using military funding as “poker chips.”

Reid said the Defense appropriations bill should be part of a larger omnibus package.

“Republicans tried this piecemeal approach already. It didn’t work,” he said.

McConnell said he was “mystified and somewhat perplexed,” by the apparent decision by Democrats to filibuster proceeding to the defense bill.

“It’s a level of dysfunction I haven’t witnessed,” McConnell said. “I thought I’d seen everything, but this is a new level of dysfunction.”

Ryan McCrimmon and Connor O’Brien contributed to this report