President Obama will not nominate a candidate for attorney general until after the midterm elections, a White House official said Tuesday.

The White House is pushing off the nomination at the request of Senate Democrats, who asked the White House to delay naming a successor to Eric Holder, who announced his resignation last month. Democrats do not want Obama's choice to become mired in election-year politics, particularly in an election in which Democrats are fighting to keep control of the Senate.

The White House will announce a nominee in early to mid-November. The timetable would force the White House to push forward the nominee during the end of the congressional session — a time when Democrats will still retain control of the Senate, regardless of the midterm outcomes.

The White House has said it has not chosen a nominee. Possible contenders include Labor Secretary Thomas Perez, U.S. Solicitor General Donald B. Verrilli Jr.; Loretta E. Lynch, the U.S. attorney for the Eastern District of New York; and Kathryn Ruemmler, the former White House counsel.

Regardless of the timing of the confirmation, it is bound to be contentious. Republicans, including Sen. Ted Cruz (R-Tex.),  have said senators should not be able to vote during the lame-duck session.

Holder announced his resignation Sept. 25 in an emotional news conference with Obama. Holder will remain in office until his successor is named.