Sen. Kyrsten Sinema opposes Democrats’ $3.5 trillion budget proposal, which seeks to fulfill key components of President Joe Biden’s economic platform and which Democrats want to approve after passing a separate bipartisan infrastructure agreement brokered by Sinema.

Aside from the $1.2 trillion bipartisan agreement now being discussed in the Senate, Democrats are likely to attempt to pass a $3.5 trillion package along party lines through a budget procedure that allows them to avoid a GOP filibuster.

Because the Senate is already divided 50-50, Sinema’s reluctance to support the Democrats’ package may compel the party to tone down some of the program’s ambitious goals in order to reduce the total cost.

“I have also made clear that while I will support beginning this process, I do not support a bill that costs $3.5 trillion — and in the coming months, I will work in good faith to develop this legislation with my colleagues and the administration to strengthen Arizona’s economy and help Arizona’s everyday families get ahead,” Sinema said in a written statement.

Speaking on the Senate floor, Senate Majority Leader Charles Schumer (D-N.Y.) claimed Democrats were “on track” to approve both bills before the August recess.

“In order to start work on a reconciliation bill, the Senate must pass a budget resolution first. And we are on track for that as well,” Schumer said.

Sinema was chastised on Twitter by radical Democratic New York Rep. Alexandria Ocasio-Cortez.

‘Good luck tanking your own party’s investment on childcare, climate action, and infrastructure while presuming you’ll survive a 3 vote House margin – especially after choosing to exclude members of color from negotiations and calling that a “bipartisan accomplishment,”‘ Ocasio-Cortez wrote.

Schumer, Senate Budget Committee Chairman Bernie Sanders (I-Vt.), and Budget Committee Democrats revealed earlier this month that the budget resolution and accompanying spending package would cost $3.5 trillion.

Sinema is a centrist whose unpredictability has irritated some Democrats.

The announcement of Sinema’s stance on the budget reconciliation bill comes on the same day that she and Ohio Senator Rob Portman revealed a significant breakthrough on a separate $1.2 trillion bipartisan public works infrastructure package.

Sanders told reporters that he expects the Democratic caucus to give him 50 votes for the budget resolution, which he expects to be debated next week.

“As I understand it, next week we’re going to have 50 votes in order to pass a 3 1/2 trillion dollar budget resolution,” he added.

If approved, the proposal would result in a massive infusion of funds targeted towards educational programs like as universal pre-kindergarten, Medicare expansion, and even climate change mitigation measures.

‘I would say that if the bipartisan infrastructure bill falls apart, everything falls apart,’ West Virginia Senator Joe Manchin, one of the chamber’s most conservative Democrats, told reporters this week.

On Tuesday, Sinema met with Biden at the White House to update him on the effort, and she and a group of ten Democratic and Republican legislators attempted to iron out remaining snags, such as budget levels for transportation, broadband, and water systems.

Senator Jon Tester (D-Montana) has said that he would vote to begin discussion. On Wednesday, Sen. Joe Manchin (D-W.Va.) told reporters that he favored going ahead with the budget resolution and that he was open to the specifics.

“I’m looking. I’m not saying whether I can or I can’t,” he said.