(CNN) - President Barack Obama is set to put forward three nominations for the influential United States Court of Appeals for the District of Columbia on Tuesday, officials told CNN.
The officials, speaking anonymously since the announcement has not yet happened, said the president will nominate attorney Patricia Millett, law professor Cornelia "Nina" Pillard, and U.S. District Judge Robert L. Wilkins to the court, which is often regarded as the second most important judicial panel in the country after the United States Supreme Court.
The court hears a significant number of key appeals over civil matters involving congressional laws and executive actions, and four of the current Supreme Court members came from there - Chief Justice John Roberts, and associate justices Antonin Scalia, Clarence Thomas, and Ruth Bader Ginsburg.
But some Republicans argue the three vacancies currently on the bench should remain unfilled, citing what they see as a relatively light caseload. They argue Obama's choice to nominate three appeals judges at once amounts to "packing" the court with ideological allies.
"It’s hard to imagine the rationale for nominating three judges at once for this court given the many vacant emergency seats across the country, unless your goal is to pack the court to advance a certain policy agenda,” Sen. Chuck Grassley, the ranking Republican on the Senate Judiciary Committee, wrote in a statement Monday.
One prior nominee to the court - Caitlin Halligan– was filibustered successfully earlier this year by Republican senators. Another nominee– Sri Srinivasan– received Senate approval earlier this year and now sits on the 8-member full-time bench. It was the president's first successful appointment to that court.
Republicans were criticized for delaying floor votes on many nominees in the president's first term in office. But the White House, too, has come under fire for not moving quickly to fill growing bench vacancies.
Some moderates from both parties have long lamented threats of delays and filibuster attempts of most presidential appointments. They say ongoing unfilled vacancies have created a crisis in many federal courts, with bulging dockets being handled by too few judges.
–CNN's Kevin Liptak contributed to this report.