U.S. Rep. Stephanie Murphy, one of the most influential moderate Democrats in the House, announced Wednesday she cannot support President Joe Biden's cornerstone $3.5 trillion Build Back Better Act as it is now written.

Murphy, of Winter Park, said in a news release issued late Wednesday that she liked much of the bill, including the "historic provisions to combat the existential threat of climate change."

But, she added, "there are spending and tax provisions that give me pause." She did not offer specifics in the news release.

"And so I cannot vote for the bill at this early stage. As this process moves forward, I remain optimistic that the comprehensive reconciliation package will be appropriately targeted and fiscally responsible — paid for by tax provisions that promote fairness but do not hurt working families," Murphy stated in the release.

Murphy is co-chair of the Blue Dog Coalition, a caucus of Democrats who are generally conservative on fiscal issues. She's used that position and her growing influence before to try to force negotiations with House leadership and the White House.

Democrats are trying to push through the Build Back Better plan as a budget reconciliation package, which could allow them to avoid being blocked by Senate filibuster.

Her vote, and the votes she influences in that caucus, would be critical to Democrats' plans to get the package through the House.

She's also looking for a fourth term in Florida's 7th Congressional District, which could be redrawn to eliminate the purple hue of the electorate she successfully appealed to through her first three terms.

Last week Murphy expressed disapproval of the Build Back Better bill as it was handled in the House Ways and Means Committee, saying there was too much not detailed for the committee. She voted against all its components and the full bill in committee.

"I care deeply — both personally and professionally — about a number of the legislative proposals we've crafted, like paid family and medical leave, access to child care, retirement security, and health profession opportunity grants," she said in the committee hearing. "More broadly, I recognize that, in order to help working families, Democrats must advance these and other proposals through the reconciliation process because of Republican obstruction."

Yet, she complained last week, too much of the bill and its background, including Congressional Budget Office scores, was not presented.

"For example, we haven't seen the subtitle on prescription drug policy, or the subtitle that will strengthen tax incentives to promote clean energy and combat climate change. Nor have we seen the revenue subtitle that will pay for all of this," she said. "So, as we begin the multi-day markup of this historic legislation, I don't know how much we're spending, how much we're raising, how we're spending some of the money, and how we're raising any of the money."