In a statement, the long-serving Democratic senator said her recovery from a case of shingles she disclosed in early March had been delayed because of complications. She provided no date for her return to the Senate and said she had asked Majority Leader Chuck Schumer to ask the Senate to allow another Democratic senator to serve in her committee seat until she was able to return.

“I intend to return as soon as possible once my medical team advises that it’s safe for me to travel,” Feinstein said. “In the meantime, I remain committed to the job and will continue to work from home in San Francisco.”

Feinstein’s decision to seek a committee stand-in during her recovery comes amid increasing anxiety within her party that her lengthy absence has damaged Democratic efforts to confirm President Joe Biden’s nominees for federal courts in a narrowly divided chamber.

She is the oldest member of Congress, at 89.

California Rep. Ro Khanna, one of two Democratic House members who called Wednesday for Feinstein to resign, said in a statement Wednesday: “This is a moment of crisis for women’s rights and voting rights. It’s unacceptable to have Sen. Feinstein miss vote after vote to confirm judges who will uphold reproductive rights.”

Khanna, a California progressive, wrote on Twitter that Feinstein should step aside. She announced in February that she would not seek reelection in 2024, opening up her seat for the first time in over 30 years.

“We need to put the country ahead of personal loyalty,” wrote Khanna, who has endorsed the Senate campaign of Democratic Rep. Barbara Lee. “While she has had a lifetime of public service, it is obvious she can no longer fulfill her duties.”

Not long afterward, Democratic Rep. Dean Phillips of Minnesota tweeted that he agreed with Khanna.

Feinstein, he wrote, “is a remarkable American whose contributions to our country are immeasurable. But I believe it’s now a dereliction of duty to remain in the Senate and a dereliction of duty for those who agree to remain quiet.”

White House press secretary Karine Jean-Pierre said Thursday from Ireland, where President Joe Biden was visiting, that Biden and first lady Jill Biden “wish Senator Feinstein the very best and a speedy recovery.” She said Biden is “deeply appreciative of her support” for his judicial nominees and “respects and appreciates her commitment to public service.”

The senator, who turns 90 in June, has faced questions in recent years about her cognitive health and memory, though she has defended her effectiveness representing a state that is home to nearly 40 million people.

Already, Democratic Reps. Lee, Katie Porter and Adam Schiff have launched Senate campaigns to succeed Feinstein.

If Feinstein decides to step down during her term, it would be up to Democratic Gov. Gavin Newsom to fill the vacancy, potentially reordering the highly competitive race. Newsom said in 2021 that he would nominate a Black woman to fill the seat if Feinstein were to step aside.

Lee is Black, and becoming the incumbent could be a decisive advantage in the contest, but it’s not known if Newsom would consider Lee, given her candidacy. Porter and Schiff are white.

Newsom declined through a spokesperson to comment on Khanna’s statement.

“The governor is not calling on her to resign,” the spokesman, Anthony York, said in an email.

Before the calls for her resignation, Democratic Sen. Dick Durbin of Illinois, chair of the Senate Judiciary Committee, acknowledged in remarks to CNN that Feinstein’s absence has slowed down their push to confirm nominees in the closely divided panel.

“I can’t consider nominees in these circumstances because a tie vote is a losing vote in committee,” Durbin said.

Feinstein has had a groundbreaking political career and shattered gender barriers from San Francisco’s City Hall to the corridors of Capitol Hill.

She was the first woman to serve as president of the San Francisco Board of Supervisors in the 1970s and the first female mayor of San Francisco. She ascended to that post after the November 1978 assassinations of then-Mayor George Moscone and City Supervisor Harvey Milk by a former supervisor, Dan White. Feinstein found Milk’s body.

In the Senate, she was the first woman to head the Senate Intelligence Committee and the first woman to serve as the Judiciary Committee’s top Democrat. She gained a reputation as a pragmatic centrist who left a mark on political battles over issues ranging from reproductive rights to environmental protection.