U.S. Senate Democrats on Thursday pressed Senate Republican chief Mitch McConnell to schedule a vote on the final confirmation of President Barack Obama's pick for attorney general.

Loretta Lynch, the current U.S. Attorney for the Eastern District of New York and a vocal supporter of Obama's immigration policies, was nominated by Obama in November to replace Eric Holder as the next U.S. Justice chief.

However, as the partisan fight over Obama's contested 2014 executive actions on immigration intensified, her confirmation became bogged down. Democrats have been criticizing the Republican-controlled Senate for deliberate foot-dragging.

"No one questions that Ms. Lynch is qualified and ready to serve, yet we are troubled that her nomination continues to languish on the Senate floor," said a letter to Senate Majority Leader McConnell, signed by all members of the Senate Democratic Caucus.

The letter noted that Lynch's nomination had been pending for 117 days by Thursday, making her the longest pending attorney general nominee in three decades.

Last Thursday, Lynch won approval from a key Senate committee -- the Judiciary Committee -- in a 12-8 vote, which sent her nomination to the full Senate. Three Republicans joined all committee Democrats in voting "yes."

To pass the final nomination vote on the full Senate floor, Lynch would just need a simple majority voting in favor of her. However, this will still be hard, considering most Republican Senators' public statements against her nomination.

If confirmed, Lynch will be the first U.S. black female attorney general.