(CNN)President Joe Biden is expected to attend a House Democratic Caucus meeting Thursday morning, according to a source familiar with the plans, as leaders press progressives to vote for a $1 trillion bipartisan infrastructure bill.

       Democratic congressional leaders have been trying to secure a framework deal on Biden's social safety net plan this week, ahead of his departure for Europe on Thursday, in order to unlock the votes needed to pass the infrastructure bill. But they've faced major divisions between moderates and progressives -- with progressives saying that just having a framework agreement on the larger spending package would not be enough to get them to support the bipartisan measure.

       The purpose of Biden's visit, which would likely delay his departure for Europe, would be to convince progressives to vote for the infrastructure bill on Thursday.

       House Democrats are huddling at 9 a.m. ET "in person" to discuss the Democratic "Build Back Better" agenda, according to a notice sent to members. Although Biden had been scheduled to leave for Europe for the Group of 20 Summit early in the morning, the White House was making plans Wednesday night to delay his departure by a few hours.

       Biden's foreign trip is a major moment on the world stage for the President, and the White House has been hoping he would at least have a framework agreement on the spending plan in hand ahead of his departure. But there are still key aspects of a potential deal that remain unresolved, including the overall price tag and how it will be paid for.

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       Although House progressives want the infrastructure bill and the larger social safety net package to move in tandem, House leadership has continued to push for a vote as early as Thursday on the infrastructure bill, even though it is not clear the votes would be there among progressives.

       Democratic Rep. Pramila Jayapal of Washington state, the head of the Congressional Progressive Caucus, on Wednesday said, "I don't think so," when asked if Biden could change her position against voting down the infrastructure bill if it comes up Thursday with the larger bill still unfinished.

       House Speaker Nancy Pelosi said on Wednesday that Democrats are "close to agreement" on the larger spending package and announced that the Rules Committee will meet on Thursday in a bid to show forward momentum.

       That does not mean an agreement will be ready by that time, however, and it is not yet clear exactly what will happen when the committee meets.

       If there is no deal and no bill text by Thursday, the committee may take witness testimony on the proposed legislation in an effort to show progress, even if they are still negotiating the policy and don't have a bill yet.

       Contours of a deal emerge

       While nothing is finalized and key sticking points remain, the contours of a potential deal are beginning to emerge.

       Pelosi on Wednesday outlined the priorities that Democrats have coalesced behind.

       In a letter to fellow Democrats, the speaker said there is "broad agreement" for universal pre-K and child care, the child tax credit, home health care, workforce development and housing. She also said "great progress has been made" to address gaps in Medicaid coverage at the state level and "we are pleased" with the climate provisions.

       But the speaker wrote that "we are still fighting for a paid family and medical leave provision."

       Democrats are now expected to scrap paid leave, discarding one of the central planks of Biden's proposal as they scramble to strike a deal with holdout senators, according to multiple people familiar with the talks.

       The plan's survival had been in question for several days due to objections from moderate Democratic Sen. Joe Manchin of West Virginia.

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       It's also unclear how Democrats will pay for the plan and whether a proposed tax on billionaires will be part of that.

       Amid resistance from Manchin and another Senate Democrat, Virginia's Mark Warner, over the billionaire tax, Democrats are once again scrambling over ways to pay for the plan. Sen. Elizabeth Warren, a Massachusetts Democrats, said on Wednesday that talks were "ongoing" with Manchin to ease his concerns.

       Manchin has also expressed concern over an expansion of Medicare to cover hearing, dental and vision benefits, another key priority for progressives.

       Senate Democrats cannot afford to lose a single vote to pass the bill under a process known as budget reconciliation. That dynamic has given every single member -- and in particular, moderates like Manchin who have pushed back on a number of the original proposals for the package -- an outsized influence over the process.

       CNN's Manu Raju, Kaitlin Collins and Kate Sullivan contributed.