U.S. Rep. John J. Duncan Jr. won't seek re-election for the East Tennessee seat he's held since 1988, he confirmed Monday in a statement.

Staff employees were notified Monday afternoon. Chief of staff Bob Griffitts confirmed the decision.

Duncan, a Republican, said Monday he was ready to retire.

“It has been a very special privilege to represent the people of the Second District in the U.S. House of Representatives. However, I will not be running for re-election in 2018."

Protesters outside Rep. Jimmy Duncan's office
<p>Protesters rallied outside Congressman Jimmy Duncan's office demanding a town hall meeting.</p>

The congressman has gained a reputation in Congress as a bit of a maverick, most obviously by voting in 2002 against U.S. entry into a war with Saddam Hussein's Iraq in 2003.

In February, Duncan raised eyebrows when he refused to hold a town hall meeting, declaring it would be an opportunity for "kooks" to turn out against him.

In July, he drew scrutiny amid reports he'd used campaign funds to employ his eldest son, John Duncan III, for several years. Duncan said his son had ably handled his campaign affairs at a salary lower than he might typically have had to pay.

On Monday, he alluded to opposition from the left. He said "never had so many" urged him to run since speculation began to spread this year that he might retire.

"Also, because of the recent attacks against me from the far left, my support among the conservative Republican base has never been more enthusiastic. I am grateful for their kind expressions of support, however, now is the time for me to move on to the next chapter of my life.

He continued: “I have decided I wanted to spend less time in airports, airplanes, and traveling around the district and more time with my family, especially my nine grandchildren, who all live in Knoxville. I love my job but I love my family more.”

Duncan, who turned 70 on July 21, took over the 2nd Congressional District seat in a special election after the death of his father, John Duncan, who also had previously served as Knoxville mayor.

Related: Burchett to announce plans Saturday

Knox County Mayor Tim Burchett said Monday morning he would be making an announcement Saturday about his future plans.

Burchett, a Republican, has said he'll seek either Duncan's seat or that of Sen. Bob Corker next year.

Rep. Jimmy Duncan_3928229
Rep. Jimmy Duncan

It's widely expected that he'll run for the 2nd District seat.

Burchett issued a statement Monday afternoon.

"I am grateful for Congressman Duncan's friendship, and I appreciate the years of service he and his family have dedicated to our community," the statement reads. "He has been a consistent, conservative voice for the 2nd District, and he's represented us well. Few families have made a bigger impact in East Tennessee than the Duncan family, and I have no doubt they will continue to make a difference."

Knoxville clinical psychologist Joshua Williams announced his plans earlier this year to seek the seat as a Democrat.

Lawyer, former judge

Duncan, the brother of state Sen. Becky Duncan Massey of Knoxville, was born in Lebanon, Tenn., in 1947.

He graduated from Holston High School and the University of Tennessee, where he studied journalism. Duncan received his law degree from George Washington University.

Duncan served as a Knox County Criminal Court judge from 1981 until 1988.

After his father's death while in office, Duncan was elected to replace him. Duncan has held the office ever since.

"During my time in Congress, I've worked as hard as I can to fight for what I believe in - fiscal conservatism, smaller government, and a more humble foreign policy that puts America first," his statement reads. "The most rewarding part of the job though has been being able to help many thouands of people on a personal level.

“I am very grateful to the people of East Tennessee for giving me the privilege to serve for what will be slightly over 30 years in Congress at the end of this term," Duncan's statement reads.

"My family has sacrificed much to allow me to serve, and I especially want to thank my wife Lynn, and my four children, all of whom have greatly helped me during my time in Congress. I also want to thank my excellent staff, especially (chief of staff) Bob Griffitts and Jenny Stansberry, both of whom have been with me the entire time I have been in this position.”

Corker offered kind words Monday in a statement.

“My friend Jimmy Duncan has represented the people of the 2nd District well for more than three decades in Congress,” said Corker. “I appreciate his no-nonsense, principled approach to public service and will sincerely miss his leadership and voice as a member of our delegation. I wish him, his wife, Lynn, and their family all the best as they prepare to enter this next chapter of their lives.”

Wrote Sen. Lamar Alexander, for whom Duncan was campaign chair in 2014: “I am proud that Jimmy Duncan has served Tennessee’s 2nd district and been my congressman for nearly three decades – and has been recognized as the most conservative member of the House for about that long. No one has done a better job of staying in touch with his constituents than Jimmy has. He has dedicated his life to service – both in Congress and as a member of the Army National Guard – and Honey and I thank Jimmy and Lynn and their family for their dedication to our state.”

Gov. Bill Haslam thanked Duncan "for his outstanding service."

Duncan Massey said in a tweet she was "proud of my brother for his service."