Democrats on the Senate Banking Committee demanded that Chair Tim Scott delay the nomination of Kevin Warsh to lead the Federal Reserve until a pair of investigations into central bank Chair Jerome Powell and Governor Lisa Cook conclude.

The Department of Justice is investigating potential criminal wrongdoing by Powell related to cost overruns on the renovation of the Fed’s headquarters. They are separately probing Cook, whom President Donald Trump has tried to fire, over allegations of mortgage fraud. Trump nominated Warsh last week to succeed Powell at the end of his term in May.

The Democratic resistance all but assures that any one Republican senator will be able to hold up Warsh’s confirmation until the probes end. The Banking Committee is comprised of 13 Republicans and 11 Democrats, meaning one Republican defection on a nomination, along with all Democrats, will deadlock the panel and prevent the nomination from reaching the floor.

“We demand that you delay any nomination proceedings for Mr. Warsh until after the pretextual criminal investigations involving Chair Powell and Governor Cook have been closed,” the Democratic senators, led by ranking member Elizabeth Warren, D-Mass., wrote.