Justice Department lawyers acknowledged Wednesday that former Alaska Sen. Ted Stevens did not receive a fair trial and are urging a federal judge to set aside his criminal conviction, saying prosecutors failed to turn over key evidence in the false statements case that contributed to the Republican senator narrowly losing his seat in Congress.

The announcement, which came April 1 in a two-page motion to dismiss the case, instantly bolstered allegations of prosecutorial misconduct made by Stevens’ lawyers at Williams & Connolly during and after the monthlong trial in U.S. District Court for the District of Columbia.