Jasper Jerome Williams, federal prisoner # 32904-077, appeals the district court’s denial of his postconviction motion requesting that the Government be made to file a motion for a downward departure of Williams’s sentence based upon his substantial assistance. Williams states that he provided substantial assistance after the Government in April 2002 had filed and the district court had granted a post-conviction Fed. R.Crim. P. 35(a) motion for a downward departure and that the Government promised to file another Rule 35 motion. ** He seeks for this court to com *681 pel the Government to file a motion for a downward departure or to order the district court to conduct an evidentiary hearing.

The Government’s failure to file a Rule 35 motion for a downward departure is discretionary and not reviewable unless the defendant makes a substantial threshold showing that the Government’s refusal was based upon unconstitutional motives, such as the defendant’s race or religion. Wade v. United States, 504 U.S. 181, 185-86, 112 S.Ct. 1840, 118 L.Ed.2d 524 (1992); United States v. Urbani, 967 F.2d 106, 109 (5th Cir. 1992). See also United States v. Sneed, 63 F.3d 381, 388-89 n. 6 (5th Cir. 1995). Williams has not made such a showing (nor indeed has he alleged any such motives).

AFFIRMED.