Stewart, who has served six terms as a Republican in the House, announced that he would leave office by the end of the year, thereby vacating his place on both the House Appropriations and Intelligence committees.
The news was first broken by the anonymous source speaking to the Salt Lake Tribune.
Gov. Spencer Cox will have to call a special election under Utah law to fill the vacancy in a region that includes Salt Lake City and much of the western side of the state, which has only four congressional districts total.
Fortunately for Republicans in the House, Stewart defeated Democratic challenger Nick Mitchell by more than 30 percentage points in last year’s election.
Stewart’s resignation also could shake up politics in the state of Utah, where Stewart was widely favored to challenge or replace Sen. Mitt Romney, who comes up for re-election next year.
“There is not a finer person than Chris Stewart,” Chaffetz told the Tribune Tuesday. “He serves with integrity and patriotism.”
Stewart’s congressional office did not respond for comment.