A key defender of President Donald Trump in the House of Representatives announced a bid for Senate Wednesday morning, but a key GOP national campaign arm is calling the move selfish and shortsighted.

"For months, I have given serious deliberation to the role I should serve that would best benefit GA, the country and [President Trump]," House Judiciary Committee ranking member Doug Collins (R-Ga.) tweeted Wednesday morning. "Today, I have officially launched my campaign for Senate to do just that."

The Georgia Republican also said on Fox News' "Fox & Friends" that "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."

The announcement will put Collins up against the Senate's newest member — Republican Sen. Kelly Loeffler — in the state's upcoming special election. Loeffler was appointed to the seat in December by Georgia Gov. Brian Kemp (R) upon the departure of former Sen. Johnny Isakson (R), who stepped down due to health problems.

During his Fox appearance, Collins — who is also a member of the president's impeachment defense team — said that he wasn't concerned that a potentially contentious intra-party showdown with Loeffler might open the seat up for a Democrat to sweep in and take the seat. But the National Republican Senatorial Committee — Senate Republicans' campaign arm — doesn't see things that way.

The committee's executive director Kevin McLaughlin criticized Collins' announcement in a statement siding with Loeffler and saying that his Senate bid would prove harmful to the party.

"The shortsightedness in this decision is stunning," the statement reads. "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."

An Atlanta Journal-Constitution poll from earlier this month shows Collins with a double-digit lead over Loeffler in favorability with registered voters — 34.5% of those polled had a favorable view of Collins with just 22.7% saying the same for the incumbent.

Under current Georgia law, Republicans and Democrats would face off in a "free-for-all" election in November, with a runoff to take place later if needed, a separate story at the Atlanta Journal-Constitution explained. However, some lawmakers in the state have been trying to pass a bill that would force Loeffler and Collins to face off in a primary election in May.