Rep. Doug Collins, R-Ga., confirmed on "Fox & Friends" Wednesday morning that he will run for U.S. Senate in a November special election, challenging incumbent GOP Sen. Kelly Loeffler -- a move that drew a stunning rebuke from the organization tasked with defending the Republican Senate majority.

"We're in for the Georgia Senate race down here. I've still got a lot of work left to do to help this president finish this impeachment out, and we're going to make a bigger announcement down here in Georgia," he told the "Fox & Friends" hosts.

The National Republican Senatorial Committee, however, slammed Collins for what it said was an ill-advised and self-centered bid for higher office.

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“The shortsightedness in this decision is stunning," NRSC Executive Director Kevin McLaughlin said in a statement. "Doug Collins’ selfishness will hurt David Perdue, Kelly Loeffler, and President Trump. Not to mention the people of Georgia who stand to bear the burden of it for years to come. All he has done is put two senate seats, multiple house seats, and Georgia’s 16 electoral votes in play. The NRSC stands firmly behind Sen. Kelly Loeffler and urges anyone who wants to re-elect President Trump, hold the GOP senate majority, and stop socialism to do the same.”

Collins will join a special election field that includes Loeffler and two Democrats, with a third Democrat likely to announce a run as well. The special election rules pit all candidates against each other – regardless of party – with a runoff in January if no candidate secures a majority of votes.

Loeffler was appointed to her seat last year by Georgia Gov. Brian Kemp, bucking President Trump, whose preferred choice for the seat previously held by retired Sen. Johnny Isakson, also a Republican, was Collins.

Collins' entrance into the race makes a runoff far more likely, which could potentially decide the balance of the Senate in a vote held in January, a month when most people are not accustomed to going to the polls.

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The Atlanta Journal-Constitution and Politico originally reported Collins was planning to announce a run, but Collins first confirmed his plans on Fox News.

A staunch supporter of Trump through the impeachment saga, Collins is likely to try to ride the president's popularity within the Republican Party to victory. Trump favored Collins over Loeffler last year when Gov. Kemp was deciding who would replace the outgoing incumbent.

Loeffler, a wealthy co-owner of the WNBA franchise Atlanta Dream, has said she will spend $20 million to retain her seat.

The Associated Press contributed to this report.