The House Republicans’ day of reckoning is almost here.

As early as Wednesday, the four corners of congressional leadership are expected to announce a sweeping budget deal that could increase the sequestration spending caps by nearly $300 billion over two years, extend the debt ceiling without any spending changes designed to reduce the deficit, and appropriate more than $80 billion for disaster relief without pay-fors.

While those rough parameters were all but certain, according to Republican and Democratic sources, as of late Tuesday leaders had yet to sign off on the deal. The negotiations were so fluid that House Democrats decided to move their retreat, scheduled for Wednesday through Friday in Cambridge, Maryland, to the Capitol complex.

The deal will set up a battle between House conservatives and GOP leadership that has long been inevitable. There will be moaning and groaning about the bipartisan agreement and a sizable number of House Republicans — likely somewhere between one third to one half of the 238-member GOP conference — could vote no.

This is not a new scenario. Past budget deals have been hammered out in a similar fashion. But it is the first such deal brokered with Speaker Paul D. Ryan fighting on behalf of the House Republicans in the four-corner negotiations.

Watch: McConnell, Schumer Hopeful About Avoiding Shutdown

Conservative revolt

While conservatives are withholding final judgement until they see what’s in the agreement, they’ve heard enough to signal it won’t be something they like — and for many, something they can’t accept.

“As a conservative, I cannot support that,” House Freedom Caucus Chairman Mark Meadows told reporters Tuesday afternoon, citing what he had heard is an “almost $300 billion plus up” on the budget caps with at least $63 billion going to nondiscretionary funding in the current and next fiscal year.

Meadows predicated that about 90 Republicans would vote against such a budget caps deal. If leaders throw in a debt ceiling extension, the defectors could reach around 100, the North Carolina Republican said.

Those defectors will almost certainly include the vast majority of the 36 hard-line conservatives in the Freedom Caucus, as well as other conservatives who are part of the larger Republican Study Committee.

“If it’s completely off the top rail then — we talked about this at [the] RSC meeting today — eventually Republicans have to draw a line in the sand because otherwise it’s disingenuous,” RSC Chairman Mark Walker said, referring to frequent GOP criticism of excessive spending in Washington.

Republican leadership aides insist the emerging deal will include some conservative wins, saying the caps deal will not provide equal increases in defense and nondefense spending and that some of the nondefense increases will be earmarked for priorities such as infrastructure and opioid abuse prevention that conservatives support.

Ryan will have some political cover in accepting a deal his members largely loathe if President Donald Trump backs it, but that may not be enough to prevent a conservative revolt once this agreement is baked into law. Still, most conservatives weren’t ready to speak about potential backlash against their leadership in their public comments Tuesday.

Speculation had already been mounting about Ryan’s future before the emerging deal, with most predicting he will not run for another term as speaker.

Watch: Trump’s ‘Treason’ Taunt and Tweets Don’t Help Immigration Talks

Democratic concerns

Ryan is not the only House leader facing threats of an intraparty rebellion surrounding the budget deal.

House Minority Leader Nancy Pelosi is facing mass pressure from her caucus to hold firm on ensuring immigration is part of any sweeping budget deal.

For months, House Democrats have withheld support for stopgap spending bills in search of a broader budget agreement on lifting the sequestration spending caps and providing a legislative replacement to the Deferred Action for Childhood Arrivals, or DACA, program that is scheduled to end March 5.

They even held firm against a Feb. 8 continuing resolution that reopened the government after a three-day shutdown last month. Many of their Senate counterparts relented to supporting that measure after Senate Majority Leader Mitch McConnell committed to holding an open floor debate on immigration, starting the week of Feb. 12 so long as the government remains open.

With the Senate looking to attach a budget caps deal to the spending bill needed to keep the government open past Thursday, the leverage House Democrats have needed to secure an immigration commitment in their chamber may finally be here and they’re ready to play their Trump card.

“The budget caps are our leverage,” House Minority Leader Steny H. Hoyer said Tuesday, noting Democrats want Ryan to commit to a floor debate on immigration like McConnell did.

The House on Tuesday are passed, mostly along party lines, a spending bill that would fund the Defense Department at $659 billion through the end of fiscal 2018, waiving the defense cap set by the sequester, and keep remaining agencies running on a CR through March 23.

The Senate is likely to switch the defense funding to a CR as well and attach language busting the sequester caps for defense and nondefense for fiscal years 2018 and 2019, as well as a debt ceiling extension and disaster relief funding. With conservatives already mounting objections a significant number of Democratic votes will likely be needed, providing them leverage.

“The Freedom Caucus and his own members are loath to do the defense and the domestic spending caps, so we’re expending them to hold in that position,” Congressional Hispanic Caucus Chairwoman Michelle Lujan Grisham said.

The New Mexico Democrat said that scenario would provide House Democrats leverage to negotiate with Ryan for floor time on an immigration bill that protects so-called Dreamers — undocumented immigrants brought to the country as children who face a deportation threat with DACA ending.

“So this week there’s significant effort at getting the House leadership to commit in the same way Senate leadership has,” Lujan Grisham said.

“And there are several bipartisan, bicameral solutions,” she added, noting the hard part is figuring out how the 50 or more moderate House Republicans who have pushed their leadership to expeditiously address the DACA issue will react.

“We’re making sure that those communications are happening this week,” Lujan Grisham said.

Hoyer suggested House Democrats will want a commitment from Ryan for an immigration floor debate before agreeing to back the budget cap deal.

Specifically, the Maryland Democrat suggested a House procedure called “queen of the hill” that would allow for votes on several immigration measures. Under the process, the bill that clears the required simple majority threshold for passage with the most votes would prevail as the House-passed bill.

Hoyer predicted a bipartisan bill from Reps. Will Hurd, a Texas Republican, and Pete Aguilar, a California Democrat, would come out on top over any conservative measure such as one by House Judiciary Chairman Robert W. Goodlatte of Virginia.

Up in the air

Still, there’s no guarantee of success for the House Democrats’ ploy.

Ryan on Tuesday reiterated that he would not bring an immigration bill to the House floor unless it has Trump’s support. The president has rejected the Hurd-Aguilar bill, as well as any measure that doesn’t fully fund a Southern border wall.

The speaker also criticized Democrats for holding government funding “hostage” to the unrelated immigration issue.

“They must stop using our troops as pawns in a game of politics,” the Wisconsin Republican said.

With the potential of the year’s second government shutdown looming, Democrats may have the high ground as Trump on Tuesday endorsed such a move if he doesn’t get his way on immigration.

“I’d love to see a shutdown if we can’t get this stuff taken care of,” he said at a White House roundtable event with law enforcement on the MS-13 gang. “If we have to shut it down because the Democrats don’t want safety … let’s shut it down.”

Virginia Rep. Barbara Comstock, who was at the meeting, rebuffed the president’s suggestion, telling him, “We don’t need a government shutdown on this.”

Comstock, who is among the GOP’s most vulnerable incumbents in November, said both parties want to avert a shutdown and noted there is bipartisan support for a crackdown on violent gangs.

Trump interjected: “You can say what you want. We are not getting support of the Democrats.”

John T. Bennett contributed to this report.