Retiring Tennessee Rep. John J. Duncan Jr. said he has no plans to endorse a fellow Republican who is planning to run for his seat.

Duncan told WBIR that Knox County Mayor Tim Burchett, who filed paperwork to run for the seat, made clear he would run for the seat regardless of Duncan’s decision.

“I always knew that I was in good enough shape to beat him if I wanted to run,” Duncan said.

In another interview with WATE said he didn’t know if he would endorse another of the Republican candidates he expects to get into the race, but he continued his criticism of Burchett.

“Tim’s about the only person who couldn’t have attacked me for being a career politician because he’s been a career politician,” Duncan said. “What can I say? I’m not thinking about that at this time.”

Duncan announced Monday he would not seek re-election in 2018 after 16 terms. Duncan first won his seat in a special election in 1988 when his father, John J. Duncan Sr., died in office.

Burchett filed paperwork to run for Duncan’s seat last week before Duncan’s announcement and is expected to declare his candidacy this weekend, the Knoxville News-Sentinel reported.

“I’ll still be making my formal announcement on Saturday,” he told the newspaper.

Burchett previously pulled his name out of the running for the state’s gubernatorial race and a primary challenge against Sen. Bob Corker.

“There’s nothing financial or otherwise has played into my decisions,” he said. “I’ve always been outspent, in every race. I’ve always had the big money be against me. They’re usually for me the day after the election. That would be true in anything.”

Inside Elections with Nathan L. Gonzales rates Tennessee’s 2nd Congressional District race Solid Republican.