Lawmakers sounded the alarm on the Justice Department’s criminal inquiry into Federal Reserve Chairman Jerome Powell, putting at risk President Donald Trump’s efforts to name a new central bank leader.

On Sunday, Powell revealed that the DOJ served the Fed with grand jury subpoenas, threatening a criminal indictment over his testimony before the Senate last June related to renovations on the headquarters, which has seen cost overruns.

He called the allegations a pretext and said the investigation was really aimed at the Fed’s ability to set interest rates without political pressure. Trump has attacked Powell for much of the last year over his reluctance to cut rates, though the president said he didn’t know about the DOJ probe.

But Republican Sen. Them Tillis agreed with Powell’s assessment and instead pointed the finger at the DOJ.

“If there were any remaining doubt whether advisers within the Trump Administration are actively pushing to end the independence of the Federal Reserve, there should now be none,” he wrote in a post on X. “It is now the independence and credibility of the Department of Justice that are in question.”