WASHINGTON, D.C. — Eleven Democratic members of the Senate Banking Committee wrote a letter to Chairman Tim Scott on Tuesday calling for the scheduled confirmation hearing for Kevin Warsh's nomination to lead the Federal Reserve to be delayed until investigations into Fed Chair Jerome Powell and Governor Lisa Cook are closed. President Donald Trump nominated Warsh, a financial executive and former Federal Reserve governor, to replace Powell as chair of the central bank.

Scott, a Republican from South Carolina, had not publicly responded to the letter as of Tuesday. The Democrats' request comes as Powell faces a criminal investigation into renovations of the Federal Reserve's headquarters, and as the Trump administration has attempted to remove Cook, a Biden appointee, from her position over alleged mortgage fraud. Cook has denied wrongdoing.

The effort to remove Cook from the Fed board has reached the U.S. Supreme Court, where justices appeared skeptical of the case for terminating her.

Trump has frequently and publicly chastised Powell over Powell's refusal to dramatically lower interest rates. Chief Judge James Boasberg of the U.S. District Court for the District of Columbia blocked the Justice Department from seeking testimony from Powell regarding his remarks to Congress on the Fed's renovation project. In his 27-page ruling last month, Boasberg wrote, "A mountain of evidence suggests that the government served these subpoenas on the board to pressure its chair into voting for lower interest rates or resigning." Powell described the criminal investigation into the headquarters renovations as a "pretext" tied to the Fed's refusal to bow to Trump's demands.

Senate Majority Leader John Thune said, "I think it's in everybody's best interest to wrap up the investigation." Sen. Thom Tillis said he would not support any nomination as long as the investigation into Powell continues.