Federal Reserve governor Stephen Miran has resigned from his position as chair of the White House’s council of economic advisers, fulfilling a pledge he made to the Senate as his assignment at the central bank becomes longer-lasting.

Miran had been on unpaid leave from his CEA post since Donald Trump appointed him last year to fill an unexpected vacancy on the Fed’s board of governors to a term that expired on 31 January. The arrangement drew the ire of Democratic senators, who said it would make a presidential puppet of the Fed’s newest policymaker.

Miran said he had been legally advised there was no need to quit his CEA post as the Fed job was only for a few months.

“I promised the Senate that if I should stay on the board past January, I would formally depart the council,” Miran said in his resignation letter dated Tuesday and reviewed by Reuters. “I believe it is important to stay true to my word while I continue to perform the job at the Federal Reserve to which you and the Senate appointed me.”

Trump on Friday announced plans to nominate former Fed governor Kevin Warsh as the next chair of the central bank to succeed Jerome Powell. While this would fill the Fed board seat currently occupied by Miran, the law allows him to serve until a successor is confirmed by the Senate.

The White House had no immediate comment on whether Pierre Yared, now the CEA’s acting chair, would be named to the top post permanently.

Miran’s resignation was first reported by Barron’s.

Miran has argued for sharply lower interest rates at every Fed meeting since he joined the central bank last September. Trump has made no secret of his desire for the Fed to reduce interest rates, and indeed made support for easier monetary policy one of his criteria for a new Fed chief.

Powell, whose leadership term ends in May, disclosed in January that the Department of Justice had launched a criminal investigation into statements he made to the Senate about Fed building renovations. Powell has described the investigation as part of a broader effort by the administration to exert control over the Fed.

The department last year also opened an investigation into Fed governor Lisa Cook for alleged misstatements on her mortgage application. She denies wrongdoing and is suing to stop Trump’s attempt to fire her in a case that is before the supreme court.

A majority of the Senate banking committee – including all its Democratic members and one of its Republican members – have decried the justice department’s investigation of Powell as political intimidation and have said they oppose moving forward on Warsh’s nomination.