A 20-year-old Pennsylvania man has agreed to plead guilty to a federal charge of making harassing phone calls in a case involving Sarah Palin's lawyers.

Shawn Christy filed notice Monday in U.S. District Court that he intends to plead guilty in an expected plea agreement with federal prosecutors.

Christy plans to plead guilty and be sentenced Dec. 1, according to the document filed by Mary Geddes, assistant federal defender.

Federal prosecutors were not immediately reachable by phone late Monday. Earlier, Assistant U.S. Attorney Retta-Rae Randall said the harassing telephone calls charge carries a maximum penalty of two years in prison and a $250,000 fine.

Christy and his father, Craig Christy, both of McAdoo, Pa., face accusations of placing harassing interstate phone calls to the former Alaska governor's lawyers in early August. Palin, the 2008 Republican vice presidential nominee, had been granted state restraining orders against them.

Both men pleaded not guilty in the case in September.