Updated

President Obama's pick to head the Justice Department's Office of Legal Counsel is withdrawing her nomination amid Republican protests over past statements she made on abortion and national security.

Dawn Johnsen said she was dropping out of the process because her "nomination has met with lengthy delays and political opposition that threaten" her objective to restore the office to its "best nonpartisan traditions" and "prevent OLC from functioning at full strength."

"I hope that the withdrawal of my nomination will allow this important office to be filled promptly," she said.

A White House spokesman said the president accepted Johnsen's request.

"Her credentials are exemplary and her commitment to the rule of law has been proven time and again, but it is now clear that Senate Republicans will not allow her to be confirmed,"  White House spokesman Ben Labolt said in a written statement.

"After years of politicization of the office during the previous administration, the president believes it is time for the Senate to move beyond politics and allow the Office of Legal Counsel to serve the role it was intended to -- to provide impartial legal advice and constitutional analysis to the executive branch," he said.

Labolt said the president will look for a replacement and call on the Senate to swiftly confirm his next nominee.

Johnsen would have been a senior aide to Attorney General Eric Holder if she was confirmed. The Senate Judiciary Committee voted along party lines last month to endorse Johnsen, the second time she had come before the committee after the Senate declined to vote on her confirmation before its session ended in December.

But her nomination had stalled ever since the March vote.

Johnsen would have been in charge of the office that formulates the attorney general's formal opinions and provides counsel on the diciest legal questions, particularly the handling of Guantanamo Bay detainees and their impending move to the Thomson Correctional Center in Illinois.

A host of GOP lawmakers have blasted Johnsen for her past statements on abortion and former President George Bush's national security policies.

One of the comments that most dismayed critics is her comparison of "forced pregnancy," or when women are unable to have abortions, to slavery.

Fox News' Kelly Chernenkoff and Shannon Bream contributed to this report.