ALEXANDRIA, Va. (AP) — A former Army Green Beret sentenced to more than 15 years in prison for spying for Russia has filed paperwork seeking to withdraw his guilty plea.

Peter Debbins of Gainesville, Virginia, filed the handwritten motion earlier this week from his jail cell in Alexandria.

He gave no reason for doing so, but the filing came less than two weeks after he was sentenced to 188 months in prison for violating the federal Espionage Act.

The sentence he received was significantly longer than the five-year term his lawyer had requested. At his sentencing hearing, Debbins said he was blackmailed by Russian intelligence agents who threatened to expose his same-sex attractions.

Prosecutors said he concocted the excuse, and cited earlier admissions that Debbins considered himself “a loyal son of Russia.” They say he provided details about activities of his Special Forces unit overseas and the names of fellow Special Forces members, among other classified information.

Prosecutors say Debbins has no basis to withdraw his guilty plea.

On Friday, two days after Debbins filed his handwritten motion, his lawyer, David Benowitz, filed a motion seeking to negate it.