By MARY CLARE JALONICK and ALANNA DURKIN RICHER

WASHINGTON (AP) — Republican Sen. Thom Tillis says he’s informed the White House that he won’t support Ed Martin, President Donald Trump’spick for top federal prosecutor in Washington, stalling the nomination in the Senate weeks before the temporary appointment expires.

The North Carolina Republican told reporters Tuesday that he had met with Martin and was opposing his nomination because of his defense of rioters who breached the Capitol on Jan. 6, 2021. Martin, a leading figure in Trump’s campaign to overturn the 2020 election, spoke at a rally on the eve of the violent riot and represented defendants who were prosecuted for the attack.

“We have to be very very clear that what happened on January 6th was wrong,” Tillis said. “It was not prompted. It was not prompted or created by other people to put those people in trouble. They made a stupid decision, and they disgraced the United States by absolutely destroying the Capitol.”

The U.S. Attorney’s office in Washington is the country’s largest and prosecuted more than 1,500 riot defendants after the 2021 attack. Trump pardoned most of the rioters the day he was inaugurated, and later appointed Martin to temporarily lead the office. That appointment expires later this month. Trump has urged Republican senators to quickly confirm him to the job.

“Ed is coming up on the deadline for Voting and, if approved, HE WILL NOT LET YOU DOWN,” Trump posted on Truth Social on Monday.

Martin could still be confirmed after his appointment expires. But Tillis’s opposition will prevent the committee from advancing the nomination, for now, and signals that Martin might not have the votes to win confirmation on the Senate floor. Senate Judiciary Committee Chair Chuck Grassley did not list Martin on this week’s agenda for votes later in the week, indicating that Republicans are aware there are not enough votes to move forward.

Martin has roiled the federal prosecutors’ office since his appointment as U.S. attorney in January, including firing or demoting veteran attorneys who prosecuted Trump supporters for storming the U.S. Capitol.

Martin has described federal prosecutors as the “president’s lawyers” and forced the chief of the office’s criminal division to resign after a dispute over a directive to scrutinize the awarding of a government contract during the Biden administration. He also demoted several senior leaders, including prosecutors who handled or oversaw politically sensitive cases involving the Jan. 6 riot and Trump allies Peter Navarro and Steve Bannon.

Tillis said he believes that anyone who broke into the building that day should be prosecuted, a disagreement he said he had with Martin.

“Whether it’s 30 days or three years is debatable, but I have no tolerance for anybody who entered the building on January 6th, and that’s probably where most of the friction was,” Tillis said.

Dozens of former federal prosecutors in the office have raised alarm over Martin’s scant courtroom experience and his actions since taking office. In a letter to the committee, more than 100 veterans of the office described him as “an affront to the singular pursuit of justice for which this Office has stood for more than two centuries.”

His supporters have touted his record fighting for conservative causes and his efforts to tackle violent crime since his appointment. About two dozen Republican state attorneys general said in a letter to the committee that Martin has “shown conclusively that he has what it takes to serve in that role with integrity and a fearless commitment to do what is right on behalf of the American people.”

It is unclear what will happen if Martin is not confirmed by May 20, the day his appointment expires. The Trump administration could replace him with another acting head and continue to press for his confirmation.

On Tuesday morning, White House spokesman Alex Pfeiffer said on social media that “Ed Martin is a fantastic U.S. Attorney for D.C. and will continue to implement the President’s law-and-order agenda in Washington. He is the right man for the job and we look forward to his confirmation.”

Associated Press writer Michelle Price contributed to this report.