The Federal Reserve is hitting back at the Trump administration as U.S. Attorney Jeanine Pirro wages a legal battle to force the central bank to hand over documents related to her criminal investigation into Chair Jerome Powell, according to a new report.Pirro's dubious probe centers around whether Powell lied to Congress about renovation cost overruns at the Fed's historic buildings. It comes amid a broader retributive campaign from Trump that targets perceived foes.Powell fired back last month with a rare public video statement, accusing Pirro of weaponizing the investigation as part of Trump's relentless pressure campaign to slash interest rates and strip the Fed of its independence. Now the Fed is fighting back in sealed courtroom proceedings, asking a judge to kill the subpoenas altogether, the Wall Street Journal reported Thursday."The fight is taking place out of public view because of secrecy rules that apply to criminal investigations pending before a grand jury," the report said.Pirro showed up at a White House event on Jan. 8, where Trump demanded his U.S. attorneys move faster on his retaliation cases. The next day, the Justice Department handed the Fed a pair of subpoenas, and it was ordered to respond by late January.The saga has thrown a wrench into Trump's plan to have Kevin Warsh replace Powell as Fed chair when his term ends in May. Senate Republicans need buy-in from Sen. Thom Tillis (R-NC), an outspoken critic of the president who has refused to budge on any Fed nomination until the investigation wraps up. Republicans lack the votes to confirm anyone without him.