WASHINGTON (AP) – As pressure builds, President Joe Biden remains focused on striking a deal and winning over two holdout Democratic senators whose support is necessary to pass a $3.5 trillion government overhaul.

Republicans remain opposed to the $3.5 trillion reconciliation bill and Democrats cannot afford to lose any votes in the deadlocked Senate. Biden chose to cancel a Wednesday trip to Chicago to dig in for another day of negotiations with lawmakers ahead of crucial votes.

Biden and his party are attempting to accomplish an extensive rewrite of the nation’s balance sheet with a slim majority in Congress. The president’s idea is to essentially raise taxes on corporations and the wealthy and use that money to expand government health care, education, and other programs.

Both Sens. Joe Manchin of West Virginia and Kyrsten Sinema of Arizona say the price tag for Biden’s plan is too hefty, but neither has publicly shared a number they can tolerate.

The two centrist senators met with the president at the White House on Tuesday as Democrats are poised to trim the vast measure’s tax proposals and spending goals to meet the overall size they are demanding.

“Really good, honest, straightforward negotiations,” Manchin told reporters back at the Capitol after his White House meeting with Biden. Manchin also confirmed that he did not give the president a new topline figure.

These behind-the-scenes actions over the $3.5 trillion measure are testing Biden’s grip on his party, as he seeks a once-in-a-generation reworking of the nation’s tax priorities and spending goals.

The source of Biden’s problems with fellow Democrats does not just exist in the Senate. A small number of centrist House Democrats are bristling at the far-reaching scope of his domestic agenda and demanding changes. But progressive lawmakers warn against cutting too much, saying they have already compromised enough.

As a way to apply pressure, progressives are threatening to withhold support for a companion bill, a $1 trillion public works measure heading to a vote Thursday, that they say is too meager without Biden’s more extensive package assured.

With all Republicans opposed to the $3.5 trillion bill, Democratic leaders can’t spare a single vote in the 50-50 Senate, relying on Vice President Kamala Harris to break a tie to pass the eventual package.

Physically holding up the bill of 2,000-plus pages, Sen. John Barrasso (R-WY) warned it was nothing but “big government socialism.”

Biden insists the price tag will be zero because the expansion of government programs would essentially be paid for with higher taxes on corporations and the wealthy. This would include businesses earning more than $5 million a year and individuals earning more than $400,000 a year, or $450,000 for couples.

Simultaneously a possible catastrophe is on the horizon as Congress courts a debt-ceiling crisis. Republicans will not keep the government funded past Thursday’s fiscal yearend nor raise the nation’s debt limit to avoid the dangerous default on borrowing. However, more votes on the situation are expected Wednesday. It is projected that a temporary solution will at least buy more time to delay the crisis from coming to fruition.

Taken together, it’s all putting the entire Biden agenda perilously closer to collapse, with consequences certain to shape his presidency and the lawmakers’ political futures.

On Tuesday, Treasury Secretary Janet Yellen told Congress in a letter that Oct. 18 is a critical date. It is the day the Treasury Department will likely exhaust all “extraordinary measures” being taken to avoid a default on the government’s obligations.

Yellen urged Congress to “protect the full faith and credit of the United States by acting as soon as possible” to either raise the debt limit or suspend it.

As a temporary solution for the Republican opposition to linking the routine government funding with the debt limit vote, Democrats are separating the two, stripping out the more-heated debate over the debt limit for another day, closer to a separate October deadline.

The Senate is poised to vote swiftly to provide government funding to avoid a federal shutdown after the Sept. 30 fiscal yearend, keeping operations flowing temporarily to Dec. 3. The House might quickly follow.

The House is also preparing a possible vote to extend the debt limit through Dec. 16, something Democrats are likely to support. But even if the House approves it, it’s unclear if it could pass the Senate in the face of GOP obstruction.

When asked by reporters about Yellen’s warning that Congress must swiftly resolve the issue, Senate Republican leader Mitch McConnell said, “Of course the debt ceiling has to be raised.”

But he insisted Democrats shoulder the unpopular vote on their own.