KNOXVILLE (AP) — Longtime U.S. Rep. John Duncan said Monday that he will not run for re-election next year because he wants to spend more time with his family.

The Knoxville Republican said in a statement that he had thought of retiring before the 2016 election, but decided to run again in Tennessee's 2nd District at the urging of his supporters.

"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," Duncan said. "I love my job but I love my family more."

The 70-year-old Duncan was first elected to Congress in a 1988 special election to replace his father, John Duncan Sr., who had cancer and died in June of that year.

Duncan said support from his conservative Republican base has never been more enthusiastic "because of the recent attacks against me from the far left."

He did not specify in the statement what those attacks were. Duncan came under fire in early July after a Knoxville website reported that he paid his son $300,000 for campaign work in the years after the younger man pleaded guilty to misconduct in office.

The congressman told the Knoxville News Sentinel that he paid John Duncan III to head his political operations and perform work ranging from putting up yard signs to fundraising. The payments were first reported by KnoxTNToday.com.

Also known as "Jimmy," the congressman is a lawyer who served as a state trial judge before entering Congress. He serves on the Transportation and Infrastructure Committee and the Oversight and Government Reform Committee in the House.

Duncan said he has fought for fiscal conservatism, smaller government and "a more humble foreign policy that puts America first."

Republican U.S. Sen. Bob Corker says he will miss Duncan's leadership in Tennessee's congressional delegation.

"I appreciate his no-nonsense, principled approach to public service," Corker said in a statement.

Tennessee Gov. Bill Haslam, also a Republican, thanked Duncan for his service to the East Tennessee district.

"As governor, and as a constituent of his district, I am very grateful to his service to our state and our country," Haslam said in a statement.

Republican U.S. Sen. Lamar Alexander said he is also Duncan's constituent.

"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," Alexander said in a statement.