Originally Published: 23 JUN 21 17:03 ET

Updated: 24 JUN 21 09:04 ET

By Lauren Fox, Manu Raju, Ted Barrett and Jessica Dean, CNN

(CNN) -- Senators on both sides of the aisle said Wednesday evening there's an agreement with White House officials and 10 senators on a bipartisan infrastructure deal, with senators planning to meet with President Joe Biden at the White House on Thursday to discuss it.

The development amounted to a significant breakthrough that could pave the way for passage of a chunk of Biden's domestic agenda -- but there are many hurdles and many landmines ahead.

The details have still not been written -- and liberal Democrats have scoffed at what they view as a paltry plan while many Republicans have yet to embrace the proposal.

And Democratic leaders said after a late-night Wednesday meeting with White House officials that they plan to employ a complex series of parliamentary steps to pass both the bipartisan plan and a much-larger Democratic only approach to dramatically expand the social safety plan. That tactic, they believe, can win over liberals who are angry their priorities were ignored by the bipartisan group.

House Speaker Nancy Pelosi and Senate Majority Leader Chuck Schumer said they would attempt to move both packages in July -- something that would require total Democratic unity, which has been lacking so far. And it would set up a jam-packed July with little floor time sandwiched between two summer recesses.

A Senate Democratic source, however, offered a more cautious timetable, saying leaders are looking at setting up the avalanche of votes -- known as a "vote-a-rama" -- on the budget resolution for the week of August 9 before lawmakers leave for recess.

Since Democrats plan to move their partisan approach through the budget reconciliation process, it can be approved with just 51 votes -- as such a plan cannot be filibustered. That process, however, typically takes weeks to play out.

But the bipartisan plan would be approved through the typical legislative order -- meaning 60 votes would be needed to overcome any Senate filibuster in a body divided 50-50.

'We have a framework'

Many details of the bipartisan plan remain scarce.

But GOP Sen. Mitt Romney of Utah and Democratic Sen. Joe Manchin of West Virginia said it's fully paid for and offsets the new spending. The total cost is $1.2 trillion over eight years, with $559 billion in new spending, multiple sources familiar with the matter tell CNN.

"Everyone in that room agreed on the framework," Manchin said, telling CNN he expects the details will be released Thursday.

The pay-fors have been fully agreed to as well, Romney said.

Infrastructure and policing legislation are two of Biden's major bipartisan priorities, and the next 24 hours could determine their fates ahead of a two-week Senate recess.

Biden was being briefed on the outline of the bipartisan infrastructure framework Wednesday evening, according to a source familiar. Biden's team was also briefing Schumer and Pelosi about the details on Capitol Hill Wednesday evening. There isn't a final agreement and there's still work ahead on a few areas, the source said, but things have moved within range of clinching a final agreement. "Not a done deal, but definitely getting there."

"We have a framework and we are going to the White House tomorrow," Sen. Bill Cassidy, one of the key GOP infrastructure negotiators, said.

Sen. Rob Portman, another lead GOP negotiator, said after leaving the meeting with the bipartisan group and White House officials that they were able to "get there" on the payfors, but still have some final details to workout.

"I think we have a good balanced group of payfors, and that was important to both sides. I will say, in good faith, we tried to get there. We didn't agree on everything, but we were able to get there," he said when asked to characterize where negotiations stand on the payfors of the infrastructure package.

Asked if they have a framework, Portman said he wouldn't use "exactly those words" Cassidy had, "but I would say, that we're very, very close."

"We're going to go back to our respective staffs and work out the details," he added.

Staffers on both sides still have to write the legislative language of their agreement, but they say the White House has signed off on the topline numbers and the pay-fors.

"White House senior staff had two productive meetings today with the bipartisan group of Senators who have been negotiating about infrastructure," White House press secretary Jen Psaki said in a statement Wednesday evening. "The group made progress towards an outline of a potential agreement, and the President has invited the group to come to the White House tomorrow to discuss this in person."

The progress comes at a crucial time.

Ahead of the two-week Senate recess, senators have been struggling to finalize the two far-reaching bipartisan deals that are the pillars of Biden's agenda. If they don't finalize an agreement, Democrats will try to go it alone on infrastructure -- a risky gambit that has no guarantee of success.

Democratic leaders have been looking at employing the budget reconciliation process to approve a sweeping plan -- potentially as high as $6 trillion -- a move that can't be filibustered in the Senate. But it would need the support of all 50 Democrats, something several have yet to back as they've called for bipartisan talks instead.

Asked to describe the difference between bipartisan talks on Tuesday and Wednesday, the source familiar said, "Night and day. People on both sides very much wanted an outcome. That's why we are where we are now."

"We are well on our way to having a $579 billion infrastructure package that's going to be taken up by the United States Senate," Democratic Sen. Jon Tester of Montana said Wednesday, acknowledging there is still some work to do.

"I think it's really important that before we go home we get the details ironed out," Sen. Susan Collins said Wednesday about the bipartisan framework. "But considering where we were and where we are, both sides negotiated in good faith. And this is important. It's important not only to the functioning of the Senate, it's important to America, and it's important globally, to show that the Senate can work together," the Maine Republican added.

How to pay for infrastructure

The challenge for the bipartisan group of lawmakers on infrastructure has been that the White House holds a different view of how to finance the plan, drawing red lines on including any new user fees like indexing the gas tax to inflation or charging drivers of electric vehicles for using America's roadways.

Republicans, meanwhile, have refused to allow any new tax increases to finance their plan. Democrats and Republicans have also engaged in a days-long discussion on how much some of their ideas for financing actually bring in.

Aides involved in the talks tell CNN that there has been a robust discussion about how much enforcing existing tax laws and forcing people to turn over unpaid money to the IRS could raise for the US government.

The Congressional Budget Office has estimated it could raise approximately $60 billion, but the White House has argued that number could be in the hundreds of billions, a massive divide that underscores the challenges of coming to a deal at all. Portman told reporters Wednesday that negotiators had decided to increase the number estimated for tax enforcement, but he did not say what that number was or if it was settled. Sen. John Thune of South Dakota, the minority whip, also told reporters earlier this week that the White House and Republicans were not in agreement about how much money in unused Covid relief funds were left on the table and could be used to finance parts of infrastructure.

Some Democrats, however, had been growing frustrated with the bipartisan talks dragging on. Sen. Elizabeth Warren, a Massachusetts Democrat, said that the bipartisan negotiators are "chewing up" too much time. She said she's concerned about "how much delay they keep putting into the process, when they recognize that's not the whole infrastructure package. It is a subset, and right off the top, before the negotiations even began, the people involved acknowledged it was not going to solve the problems that we face on infrastructure."

Added Democratic Sen. Richard Blumenthal of Connecticut, "I'm certainly out of patience and we're running out of time on infrastructure."

Yet the Senate deal-making Democrats have been urging patience.

"Some of the progressive members of my caucus have been saying that for weeks," said Sen. Chris Coons of Delaware, a close Biden ally. "I've reminded them repeatedly that in a 50-50 Senate, where several members said publicly they will not vote for reconciliation until we make our best efforts on infrastructure, I think we're at our last best (chance) at a bipartisan infrastructure package."

Manchin is one of those Democrats -- and he's refused to back a party-line approach to approve a much bigger package that includes expanding the social safety net.

"Well, you know me, I never give up," Manchin said when asked if he'd endorse going the reconciliation route if the talks collapse.

Policing The fragile state of infrastructure negotiations is mirrored in another one of Biden's legislative priorities: legislation to overhaul the nation's policing laws.

After months of discussions, Republican Sen. Tim Scott of South Carolina and Democratic lawmakers Rep. Karen Bass of California and Sen. Cory Booker of New Jersey have yet to find an agreement on how to tackle the scourge of police violence around the country. This comes after Scott said earlier this month that a deal needed to come together in June if the group was going to be successful. That group has spent months trying to find a middle ground on the issue reforming qualified immunity, which currently protects cops from being sued in civil court. The group has also struggled with the federal statute that governs when a police officer can be held criminally liable.

Bass told CNN on Wednesday afternoon there are still major issues that have to be resolved.

The California Democrat said she's "hoping to talk to both senators again and see what where we get, that's the bottom line. You know that things can come together very quickly at the last minute and that tends to be what happens, so that's what I'm hoping for."

Asked if she believed the prospect of getting a deal done was looking more precarious, Bass said, "I do, and that's only because of time. I mean the question is, the Senate is going out for two weeks. Senator Scott has said June or bust, which I appreciated, I was glad he did that. So, the question will be what happens in the next 24 hours. I just don't know."

On Tuesday, Scott told CNN the group was "very, very close, but we're not quite there," adding, "we best have something" before the Senate leaves on Thursday.

Booker told reporters Wednesday that Thursday was shaping up to be a make-or-break day for the policing talks.

"Principles will have to decide," he said when asked what would happen if there is no deal by Thursday.

'I think today is pretty critical'

Already on Tuesday, another one of the Democrats' key agenda items failed on the floor of the US Senate. All 50 Democrats voted to advance the sweeping voting and ethics reform bill, but all 50 Republicans rejected it, effectively killing the bill for now.

The repeated defeats are emboldening progressives to argue that the time for bipartisanship during the Biden administration is coming to an end. After six months and with the midterm campaign season just around the corner, some Democrats have argued they should be focusing more on what they can do alone.

The Senate Budget Committee is trying to find consensus by next Monday on their budget resolution language, which would be the first step in a process that would allow Democrats to pass their infrastructure bill with just 50 votes. And a series of Democrats have urged President Joe Biden to get more involved in pushing to end the filibuster even as several moderates have been clear they don't want to touch the procedural tool, which protects the rights of the minority party.

"I think today is pretty critical," Tester said. Asked if he believed it was possible to get a deal after the recess, he said bluntly, "I think we just (have) run out of time."

This story has been updated with additional reporting.