Washington- Harriet Miers withdrew her nomination to be a Supreme Court justice Thursday in the face of stiff opposition and mounting criticism about her qualifications.

President Bush said he reluctantly accepted her decision to withdraw, after weeks of insisting that he did not want her to step down. He blamed her withdrawal on calls in the Senate for the release of internal White House documents that the administration has insisted were protected by executive privilege.

“It is clear that senators would not be satisfied until they gained access to internal documents concerning advice provided during her tenure at the White House _ disclosures that would undermine a president’s ability to receive candid counsel,” Bush said. “Harriet Miers’ decision demonstrates her deep respect for this essential aspect of the constitutional separation of powers _ and confirms my deep respect and admiration for her.”

Miers’ surprise withdrawal stunned Washington on a day when the capital was awaiting news on another front _ the possible indictment of senior White House aides in the CIA leak case.

Miers notified Bush of her decision at 8:30 p.m., according to a senior White House official who said the president will move quickly to find a new nominee.

In her letter dated Thursday, Miers said she was concerned that the confirmation process “would create a burden for the White House and our staff that is not in the best interest of the country.”

She noted that members of the Senate had indicated their intention to seek documents about her service in the White House in order to judge whether to support her nomination to the Supreme Court. “I have been informed repeatedly that in lieu of records, I would be expected to testify about my service in the White House to demonstrate my experience and judicial philosophy,” she wrote.

“While I believe that my lengthy career provides sufficient evidence for consideration of my nomination, I am convinced the efforts to obtain Executive Branch materials and information will continue.”

Miers’ nomination has been under withering criticism ever since Bush announced her selection on Oct. 3. There were widespread complaints about her lack of legal credentials, doubts about her ability and assertions of cronyism because of her longtime association with Bush.

Most recently she has been Bush’s White House counsel. Bush said that with her withdrawal, she would remain as counsel. He did not indicate when he would name a successor.

“My responsibility to fill this vacancy remains,” Bush said in a statement. “I will do so in a timely manner.”

Before Bush chose Miers on Oct. 3, speculation focused on Miers and two other Bush loyalists: Attorney General Alberto Gonzales, Bush’s longtime friend who would be the first Hispanic on the court; and corporate lawyer Larry Thompson, who was the government’s highest ranking black law enforcement official as deputy attorney general during Bush’s first term.

Other candidates mentioned frequently included conservative federal appeals court judges J. Michael Luttig, Priscilla Owen, Karen Williams, Alice Batchelder and Samuel Alito; Michigan Supreme Court justice Maura Corrigan; and Maureen Mahoney, a well-respected litigator before the high court.