Hours before President Trump is scheduled to meet with Republican senators on Capitol Hill, he rekindled his feud with a GOP senator from Tennessee who has criticized the administration, saying Bob Corker “couldn’t get elected dog catcher.”

“Bob Corker, who helped President O give us the bad Iran Deal & couldn’t get elected dog catcher in Tennessee, is now fighting Tax Cuts,” Trump posted on Twitter.

The president also repeated his claim that Corker, who will not seek re-election next year, decided not to run because Trump didn’t endorse him.

“Corker dropped out of the race in Tennesse when I refused to endorse him, and now is only negative on anything Trump. Look at his record!,” Trump tweeted, misspelling Tennessee.

Corker later turned to twitter himself to fire back at Trump.

“Same untruths from an utterly untruthful president. #AlertTheDaycareStaff​,” Corker wrote.​

In an interview with CNN, Corker rebuked Trump as “harmful to our nation” and said the president is “unable to rise to the occasion.”

“I think the things that are happening right now that are harmful to our nation, whether it’s the breaking down of … relationships we have around the world that have been useful to our nation,” Corker said. “But I think at the end of the day, when his term is over, I think the debasing of our nation, the constant non-truth telling, just the name-calling … I think the debasement of our nation will be what he’ll be remembered most for, and that’s regretful.”

Trump then returned to the social messaging site to blast Corker once again, resurrecting the moniker “liddle’ Bob Corker” he used in a tweet earlier this month.

“Sen. Corker is the incompetent head of the Foreign Relations Committee, & look how poorly the U.S. has done​,” Trump posted. “He doesn’t have a clue as​ the entire World WAS laughing and taking advantage of us. People like liddle’ Bob Corker have set the U.S. way back. Now we move forward!​”​

Their tit-for-tat attacks erupted earlier Tuesday after Corker appeared on ABC’s “Good Morning America” and ​said he stands by his comments that the White House is an “adult day care center” and that Trump’s leading the United States into “World War III.”

“I don’t make comments I haven’t thought about,” ​he said on the show.

The senator said he hopes the president stays out of the debate over tax reform.

“What I hope is going to happen is the president will leave this effort, if you will, to the tax-writing committees, let them do their work and not begin taking things off the table that ought to be debated in these committees at the proper time,” Corker told ABC.

Corker’s comments come as Trump intends to sit down with GOP senators during a lunch on Capitol Hill later Tuesday to discuss the tax reform package.

Corker blasted Trump’s visit as a “photo-op.”