Rep. Jason Chaffetz speaks during a town hall meeting, Feb. 9, 2017, in Cottonwood Heights, Utah.
Rep. Jason Chaffetz speaks during a town hall meeting, Feb. 9, 2017, in Cottonwood Heights, Utah.

A key U.S. Republican congressman who said this week he would not seek re-election or run for any other office next year now says he may leave Congress before his term in the House of Representatives runs out in early 2019.

Congressman Jason Chaffetz, chairman of the House Oversight Committee, rose to prominence on Capitol Hill through his dogged investigations of Democratic presidential candidate Hillary Clinton before the 2016 election.

Chaffetz made headlines Wednesday when he wrote on Facebook: "After long consultation with my family and prayerful consideration, I have decided I will not be a candidate for any office in 2018." He made his decision more specific Thursday, saying: "My future plans are not yet finalized, but I haven't ruled out the possibility of leaving [Congress] early."

Chaffetz has been mentioned as a possible candidate for governor of Utah, or for one of the state's two U.S. Senate seats. He did not mention those possibilities in announcing his decision to leave the political arena, just five months after his re-election to Congress for a fourth term.

"Let me be clear I have no ulterior motives," Chaffetz wrote on Facebook. "I am healthy. I am confident I would continue to be re-elected by large margins. I have the full support of Speaker [Paul] Ryan to continue as chairman of the Oversight and Government Reform Committee."

Chaffetz was re-elected four times in one of the most Republican congressional districts in the country. However, he has been confronted with an unexpected challenge from Democratic newcomer Kathryn Allen. Allen raised more than a half-million dollars in the first three months of 2017, partly in reaction to Chaffetz's comment during the Capitol Hill debate on health care, when the Utah congressman suggested Americans of limited means should devote more of their income to buying health insurance, instead of purchasing expensive iPhones.

As House Oversight chairman, Chaffetz also was strongly criticized by Democrats for saying he had no intention of investigating possible conflicts of interest between Trump's global business empire and his presidency. Before last year's election, Chaffetz had vowed he would investigate Clinton "for years" if she won the presidency over Trump.

Chaffetz is at least the seventh House Republican this year to resign or announce retirement plans; those seven include four members who left to join Trump's Cabinet.

In his public farewell on Facebook, Chaffetz did not close the door entirely on the possibility of another foray into politics: "After more than 1,500 nights away from my home, it is time. I may run again for public office, but not in 2018."