WASHINGTON (AP) — Democrats’ efforts to temporarily replace California Sen. Dianne Feinstein on the Senate Judiciary Committee met quick opposition Monday from Republicans, complicating their plan as some of President Joe Biden’s judicial nominees remain on hold during her extended medical absence.

Feinstein, 89, last week asked to be temporarily replaced on the Senate Judiciary Committee while she recuperates in her home state from a case of the shingles. The statement came shortly after a member of California’s House delegation, Democratic Rep. Ro Khanna, called on her to resign from the Senate, saying it is “unacceptable” for her to miss votes to confirm judges who could be weighing in on abortion rights, a key Democratic priority. Feinstein has been away from the Senate since February.

Senate Majority Leader Chuck Schumer, D-N.Y., said Monday that he is moving forward and hopes to put a resolution on the Senate floor this week seeking a temporary substitute on the panel. But it’s unclear if Democrats will have the votes.

Multiple Republicans indicated on Monday that they would object to the rare request, meaning there would have to be a roll call vote — and Democrats would need at least 10 Republicans to vote with them for approval.

Texas Sen. John Cornyn, a Republican on the Judiciary committee, said on the Senate floor that he hopes to see Feinstein back in the Senate soon, but “until then, President Biden’s most controversial, partisan judicial nominees will have to wait.”

Iowa Sen. Joni Ernst, a member of Republican leadership, said she wouldn’t support a temporary replacement. “We’re not going to help the Democrats with that,” she told reporters.

The uncertainty over Feinstein’s status, and over the fate of some of Biden’s judicial nominees, is the latest tangle for Schumer as he navigates his party’s one-seat majority in the Senate. Feinstein’s absence comes as another Democratic senator, John Fetterman of Pennsylvania, has also been on an extended medical leave. Fetterman, 53, returned to the Senate on Monday after checking himself into the hospital in February for clinical depression.

It also comes as bipartisan votes on federal judgeships — lifetime appointments, in most cases — have been increasingly steeped in partisanship. While the Judiciary committee has moved some of Biden’s judicial nominees with a handful of GOP votes, Republicans are loath to give approval to a plan that will help Biden place more judges on the bench.

“I will not go along with Chuck Schumer’s plan to replace Senator Feinstein on the Judiciary Committee and pack the court with activist judges,” tweeted Sen. Marsha Blackburn, R-Tenn., a member of the Judiciary panel.

Democrats say the are currently 12 federal judge nominees they have been unable to advance because of Feinstein’s absence. It is unclear how many of the nominees would be able to move with some Republican support.

Several Republicans questioned the motivations behind the effort. North Carolina Sen. Thom Tillis said he was skeptical because Democrats aren’t trying to replace Feinstein on the Intelligence or Appropriations panels.

“Why one and not all three?” asked Tillis, who is also a member of the Judiciary Committee.

Republican Sens. Susan Collins of Maine and Chuck Grassley of Iowa said they think Democrats are pressuring Feinstein unfairly.

Collins said that she and Feinstein are good friends, and she thinks there has been a “concerted campaign” to push her off the Judiciary committee. “I will have no part of that,” Collins said.

Feinstein has come under increasing pressure to resign or step down from her duties. While she has defended her effectiveness, she has faced questions in recent years about her cognitive health and memory, and has appeared increasingly frail.

In 2020, she said she would not serve as the top Democrat on the Judiciary panel after criticism from liberals about her handling of of Justice Amy Coney Barrett’s confirmation. Earlier this year, she said she would not serve as the Senate president pro tempore, or the most senior member of the majority party, even though she was in line to do so. The president pro tempore opens the Senate every day and holds other ceremonial duties.

Iowa Sen. Chuck Grassley, a longtime member of the panel who is the same age as Feinstein, chastised Democrats for denying Feinstein the opportunity to become chairman of the committee and trying to force her out of office “because she’s old.”

“I don’t intend to give credence to that sort of anti-human treatment,” Grassley said.

If Feinstein were to resign immediately, the process would be much easier for Democrats, since California Gov. Gavin Newsom would appoint a replacement. The Senate regularly approves committee assignments for new senators after their predecessors have resigned or died. But a temporary replacement due to illness is a rare, if not unprecedented, request.

It is unclear how long Feinstein will be away. Her office has not given a timeline for her return, and Democrats have not said for how long they would seek a temporary replacement. She has been away from the Senate since Feb. 27, just two weeks after she announced she would not run for another term next year.

Schumer said he spoke to Feinstein in recent days, and “she believes she will return soon. She is hopeful of that and so am I.”

Asked if Feinstein should resign, Senate Judiciary Committee Chairman Dick Durbin said Monday that “I’m not going to push her into any other decision.” Durbin had previously expressed frustration about his committee’s stalled nominees.

Durbin appealed to his Republican colleagues to “show a little kindness and caring for their colleague.”

If the Senate votes to replace her on the panel, “I think we can take care of this issue, do it very quickly,” Durbin said. “I hope we can find 10 Republicans who will join us in that effort.”