U.S. Federal Reserve Chair Jerome Powell said on Sunday that the Trump administration has threatened him with a criminal indictment over testimony he provided to Congress last June, Reuters reported.

The Department of Justice served grand jury subpoenas to the Federal Reserve on Friday, an unprecedented step in the dispute between Powell and President Donald Trump over interest rate policy. Bloomberg reported that Powell described the subpoenas as a “pretext” and said they should be understood in the “broader context of the administration’s threats and ongoing pressure.”

In a written and video statement, Powell clarified that the subpoenas relate to his testimony on ongoing renovations at the Fed’s headquarters. He said the action underscores a fundamental question for the central bank: whether monetary policy will continue to be guided by evidence and economic conditions, or be subject to political pressure and intimidation. “The threat of criminal charges is a consequence of the Federal Reserve setting interest rates based on our best assessment of what will serve the public, rather than following the preferences of the president,” Powell said.

Financial markets reacted immediately. The US dollar weakened across major currencies, gold extended gains to record highs, and S&P 500 futures fell 0.3 percent, Bloomberg reported.

The subpoenas represent a further escalation of President Trump’s long-standing feud with Powell. The president has repeatedly called for aggressive rate cuts and has publicly suggested firing the Fed chair. Trump has also attempted to remove Fed Governor Lisa Cook, a case set to be considered by the Supreme Court later this month.