(CNN) —  

The White House mobilized an all-out Capitol Hill lobbying blitz Wednesday afternoon in the hope of salvaging an immigration bill in the House that would give Trump his long-awaited border wall as well as a solution for family separations at the border.

After a week of back and forth, unclear signals, confusion and a visit from President Donald Trump to Capitol Hill, the White House launched its most aggressive effort since health care to unite Republicans and advance the House’s immigration compromise bill along despite its uncertain path to the passage.

The scramble for votes came as Trump announced he would “sign something” to tackle family separations, a move that caught Hill leaders off guard and injected uncertainty into whether the move could endanger the House’s compromise bill as leaders rushed to get to 218 votes.

“I’ll be signing something in a little while that’s going to do that,” Trump said Wednesday in reference to family separations at the border. “I’ll be doing something that’s somewhat preemptive and ultimately will be matched by legislation I’m sure.”

As part of the effort to sell the compromise bill, Majority Whip Steve Scalise gave the White House a list of people the President personally needed to convince. And later that afternoon, nearly two dozen members boarded white vans – alongside GOP leaders – to go straight to the White House to meet with Trump.

Meanwhile, Sen. Jeff Sessions, the attorney general and well-known immigration hardliner from his days on Capitol Hill, meet with the Republican Study Committee and made his pitch for the compromise bill while Department of Homeland Security Secretary Kirstjen Nielsen, according to two aides, was expected to also travel to the Hill to meet with more members on immigration.

It’s the kind of administration effort that House leaders have been asking for days, but the question of whether it would be enough to sway members – especially with just 24 hours until a vote – remained to be seen.

Republicans across Capitol Hill are still deeply divided over how to solve the issue of DACA and stop families from being separated when they come to the US. Leadership in the Senate and the House appear to be mulling conflicting approaches for how to handle the situation at the border – whether to go big with a broader immigration package or go narrow on a specific bill addressing family separation.

Before Trump announced his plans for an executive order, House Speaker Paul Ryan repeated Wednesday that his chamber is planning to vote in 24 hours on a pair of bills, one bill a conservative option without enough support to pass and another a broader immigration package that includes language to keep families together while they’re processed at the border. GOP leaders are backing that option though it also lacks support it needs as of Wednesday morning.

“The administration wants Congress to act and we are,” Ryan told reporters Wednesday, adding, “I hope we will be able to pass this tomorrow.”

House leadership doesn’t have the votes yet on their broader package, a fact that Rep. Tom Cole, a member of the GOP whip team, confirmed Wednesday morning to reporters. While leaders had long said that the conservative bill likely wouldn’t pass, the question is whether they can convince members to get behind a compromise bill, which includes $25 billion in border security funding including money for the wall, a path to citizenship for recipients of the Deferred Action for Childhood Arrivals program and a fix to address in part family separations at the border.

Ryan would not address what Plan B is if the compromise legislation does not pass in the House. He quipped “this bill is Plan B” and would not answer if he would entertain a standalone, narrow bill focused just on family separation – as Senate Republicans are considering — saying only that they would “cross that bridge” when they come to it.

House Majority Leader Kevin McCarthy tried to present this compromise bill as the only option.

“This is a bill the President supports,” said the California Republican who’d like to replace Ryan when he retires. “This is a bill that can become law.”

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House Republicans on both the moderate and conservative side of the conference have expressed concerns, a potentially large enough number to sink the bill if House leaders can’t change minds rapidly over the next few hours.

“I think getting this compromise bill to the finish line is going to be a lot more challenging than I would have anticipated,” said Rep. Ryan Costello, a Republican from Pennsylvania, before Trump announced his executive order.

The conservative House Freedom Caucus is also holding out votes.

“I think from my standpoint, we need to keep working on it,” said Rep. Scott Perry, a conservative from Pennsylvania.

House leaders had hoped that Trump’s visit to Capitol Hill Tuesday evening would help move at the very least conservative members in their direction, but according to multiple members and aides in the room, Trump’s presentation was classic Trump: a bit disjointed, wide-ranging and not all that clear about why or how much he was backing each immigration proposal.

“We’ve been burned too many times by him to just go all in because he showed up,” one House GOP member who is still on the fence told CNN. “He was good – said he was behind us, that he loved us, but it wasn’t a game changer by any means.”

The rush for House votes, of course, is just part of the equation. Over in the Senate, Majority Leader Mitch McConnell told reporters Tuesday that all the members of his conference supported finding a solution to family separations at the border, but what that looks like is unclear, and that worries their counterparts in the House.

“One of my concerns is whether it will pass the Senate. I want legislation to pass,” said New Jersey Republican Leonard Lance, a moderate. “I whipped undecided. I don’t want to be too negative and I don’t want to be too positive. I’m undecided.”

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Another complicating factor is that Democrats would be needed to pass anything in the Senate and how much Democratic support GOP Senate leaders could count on is at best unclear. Many Democrats have consistently put the blame back on Trump to reverse his “zero-tolerance” policy that has led to the current issue along the border.

CNN’s Ashley Killough, Phil Mattingly and Sunlen Serfaty contributed to this report.