President Joe Biden has scheduled meetings Tuesday with two Senate holdouts within his own party as part of a last-minute bid to secure support for a $3.5 trillion social spending plan. 

Sens. Joe Manchin, D-W.Va., and Kyrsten Sinema, D-Ariz., are openly opposed to the package out of concern for its hefty price tag and questions about how it will be paid for. 

Biden will hold separate talks with the senators to try and assuage their concerns about the package. Their votes are especially critical in the evenly divided Senate where the president cannot afford any "No" votes from his party if it hopes to pass the bill by means of budget reconciliation. 

A CNN correspondent tweeted that Sinema did not take questions after leaving the White House. Manchin will meet with Biden in the afternoon, according to a Washington Post report.

By securing votes from Manchin and Sinema, Biden and his allies hope to free up legislators in the House to vote on a smaller $1.2 trillion physical infrastructure bill that they support. Speaker Nancy Pelosi has stated her intent to bring the bill to a vote on Thursday, but she needs to ensure more progressive members of her caucus do not withhold their support. 

They previously made clear that they will not allow a vote on the bill without first seeing the larger “human infrastructure” bill sent to the Senate for consideration. Pelosi has said that it is “self-evident” that the price tag may need to be trimmed, something that could prove to be anathema to House progressives who previously wanted a $6 trillion spending plan before settling on the current $3.5 trillion.

On Tuesday, however, she maintained that both bills will be passed. 

Manchin and Sinema have been the most reluctant Democratic senators in shepherding Biden’s Build Back Better plans through a narrowly controlled Congress. Both are representing Republican-leaning states and have faced criticism for tacking closer to the center.

Manchin in particular has drawn scorn from progressive Democrats for playing the role of foil to their domestic agenda. He has repeatedly said that he will not budge on his opposition to the $3.5 trillion plan, which he insisted before was “not urgent” for Congress to pass. 

Sinema has drawn criticism for fundraising from opponents of the $3.5 trillion deal.