A Democratic nominee for the Federal Election Commission has pulled his name from consideration, a move that may further prolong the Senate impasse over filling four FEC vacancies.

Democrats had hoped to return Robert Lenhard, a former chairman of the commission, to the FEC. But Lenhard no longer wants to be considered due to the delay over the nomination process, according to a letter from Senate Majority Leader Harry ReidHarry ReidDraft House bill ignites new Yucca Mountain fight Week ahead: House to revive Yucca Mountain fight Warren builds her brand with 2020 down the road MORE (D-Nev.) to White House chief of staff Joshua Bolten.

"[Lenhard] is exceptionally well-qualified and his nomination is not controversial," Reid wrote. "However, given the complete unwilligness among Republicans to constitute a functional FEC, I could not assure him of timely confirmation."

Senate Democrats have held up votes to confirm the four pending nominees due to their objection to Republicans' choice of Hans von Spakovsky. While Republicans have called for one vote to confirm all four nominees as a bloc, Democrats have sought a separate vote for each nominee, believing that von Spakovsky does not have enough support for confirmation. Democrats, led by Barack ObamaBarack ObamaTrump team did background check on Flynn, knew of Turkey ties: report Trump: 'I couldn't care less about golf' Top Obama official to replace Chris Dodd as MPAA head MORE, have concerns over von Spakovsky's voting rights record in Georgia and as a lawyer in the Department of Justice.

Reid wrote that the search for a new Democratic nominee and the process to get one confirmed typically takes seven months.

The FEC has only two current members, which isn't enough for a quorum.

Read Reid's letter here (.pdf).