WASHINGTON (AP) — Federal Reserve Chair Jerome Powell will attend the Supreme Court’s oral argument Wednesday in a case involving the attempted firing of Fed governor Lisa Cook, an unusual show of support by the central bank chair.

The high court is considering whether President Donald Trump can fire Cook, as he said he would do in late August, in an unprecedented attempt to remove one of the seven members of the Fed’s governing board. Powell plans to attend the high court’s Wednesday session, according to a person familiar with the matter, who spoke on condition of anonymity.

It’s a much more public show of support than the Fed chair has previously shown Cook. But it follows Powell’s announcement last week that the Trump administration has sent subpoenas to the Fed, threatening an unprecedented criminal indictment of the Fed Chair. Powell — appointed to the position by Trump in 2018 — appears to be casting off last year’s more subdued reponse to Trump’s repeated attacks on the central bank in favor of a more public confrontation.

Powell issued a video statement Jan. 11 condemning the subpoenas as “pretexts” for Trump’s efforts to force him to sharply cut the Fed’s key interest rate. Powell oversaw three rate cuts late last year, lowering the rate to about 3.6%, but Trump has argued it should be as low as 1%, a position few economists support.

The Trump administration has accused Cook of mortgage fraud, an allegation that Cook has denied. No charges have been made against Cook. She sued to keep her job, and the Supreme Court Oct. 1 issued a brief order allowing her to stay on the board while they consider her case.

If Trump succeeds in removing Cook, he could appoint another person to fill her slot, which would give his appointees a majority on the Fed’s board and greater influence over the central bank’s decisions on interest rates and bank regulation.