The criticism from the Fed was only the latest to hit the Republican plan to cut taxes by up to $6 trillion.
It has also been assailed by Democrats as benefiting the wealthiest Americans while raising taxes on middle class Americans and cutting spending on social programs, including the Medicare and Medicaid healthcare programs.
Republican lawmakers are questioning a proposal to help pay for tax cuts by eliminating popular tax deductions. Some Republican fiscal hawks have warned they will not back a tax reform package that adds to the deficit.
The Trump tax plan would add about $2.4 trillion to the deficit over the next decade, said the nonpartisan Tax Policy Center, a Washington tax think tank, at a time when the national debt already exceeds $20 trillion.
"Where is all that money coming from?" Representative John Yarmuth, the top Democrat on the House Budget Committee, asked on the House floor. "If you're listening to this and you're not a millionaire, probably from you."
In the Senate, Democrats sought to hamstring the Republican budget resolution with amendments that would prevent tax legislation from benefiting the wealthy, raising taxes on the middle class and adding to the deficit.
Democrats also called for an end to reconciliation, the legislative procedure that would sideline them in a Senate vote. (Additional reporting by Howard Schneider and Ann Saphir.)
This article was provided by Reuters.