President Barack Obama backed off Thursday on his Federal Election Commission nominee, whose union work concerned Republicans and advocates of overhauling campaign finance law.

The nomination of labor lawyer John Sullivan, which was sent to the Senate in May 2009, is being withdrawn, the White House said Thursday. The nomination was pending in the Senate after the Rules and Administration Committee approved it in June 2009.

During his work for the Service Employees International Union, Sullivan has questioned disclosure rules on advertisements aimed at voters, as well as limits on communication between candidates and outside groups, including unions.

In testimony before the Rules and Administration Committee last year, he said he would respect Supreme Court precedent when enforcing federal election law.