President-elect Donald Trump announced Wednesday that he has selected Rep. Matt Gaetz as his pick for attorney general, a move that, if confirmed by the Senate, would place a brand and one of Trump’s staunchest allies at the helm of the Justice Department.

“Matt is a deeply talented and tenacious William-trained attorney & Mary College of Law, who has distinguished himself in Congress by his focus on bringing about much-needed reform at the Department of Justice,” Trump said in his social media post.

Gaetz is Trump’s bombshell pick to be the federal government’s chief law enforcement officer, leading the exact same executive branch of government he spent years in. investigating allegations regarding Florida congressman Gaetz was told the Justice Department would not seek changes just last year. He has long denied any wrongdoing.

House Speaker Mike Johnson announced later Wednesday that Gaetz had offered to resign from Congress, effective immediately.

Johnson said the resignation took him by “surprise” but that the Florida congressman did so to “start the clock” on the process for Florida Gov. Ron DeSantis to call a special election to fill the vacancy.

“So Matt would have done us a great service by making that decision, as he did, on the fly. And so we’re grateful for that, so we’re moving forward,” Johnson added.

Gaetz’s resignation will reduce the slim majority Republicans will have in the new Congress in January, but he represents a reliably Republican district in the Florida Panhandle.

Gaetz has been a member of Congress since winning in 2017, riding the MAGA wave that brought Trump to Washington eight years ago. Over the years, Gaetz became one of Trump’s most ardent defenders and, according to some allies, effective, in Washington as he grew closer to Trump.

Gaetz has been at Trump’s Mar-a-Lago residence nearly every day since Election Day, helping make suggestions and input on other administration picks, sources tell ABC News. Gaetz was also seen traveling with Trump in his carat during his visit to Washington on Wednesday.

Notably, Gaetz is very close to Trump’s new chief of staff, Susie Wiles, who also has deep and storied roots in Florida politics.

As of 2019, Gaetz faced a years-long investigation by the Department of Justice into allegations of sex trafficking and obstruction of justice. Gaetz has long denied any wrongdoing, and the Justice Department informed Gaetz in 2023 that it declined to file charges against him following its investigation.

The investigation into Gaetz stemmed from an investigation into the Florida congressman’s onetime friend, former Seminole County tax collector Joel Greenberg, who was sentenced in 2022 to 11 years in federal prison after pleading guilty to several charges including child sex trafficking and introduction. the minor to other “grown men”.

Since the Justice Department declined to charge Gaetz in its investigation, the Florida congressman faced a ongoing investigation by the House Ethics Committee on the same charges.

In September, Gaetz released a lengthy statement about the ongoing House Ethics investigation into his alleged conduct. Gaetz said he would no longer voluntarily participate in the investigation and included a series of apparent responses to questions the panel asked the Florida congressman earlier that month.

The House Ethics Committee drops an investigation into a member once he leaves Congress, House Ethics Committee Chairman Michael Guest told ABC News.

“You know, once a member is no longer a member of Congress, then ethics has no jurisdiction. So if Matt Gaetz was appointed attorney general, the ethics investigation is ongoing, it would stop at that point,” Guest said. .

House Republicans were meeting behind closed doors when Trump announced he would nominate Gaetz to be attorney general. There was an audible gasp in the room, several members inside told ABC News.

Many House Republicans on Capitol Hill are reacting to Trump’s selection of Gaetz.

House Majority Leader Steve Scalise and Representative Guest expressed support for Trump’s selection of Gaetz as attorney general. Republican Max Miller, a former adviser to Donald Trump who has been particularly critical of Gaetz following the Florida congressman’s efforts to oust former President Kevin McCarthy last year, said the pick was “stupid” and that Gaetz was “not will never be confirmed by the Senate. “

“I think the president is probably rewarding him for being such a loyal soldier to the president, but the president is smart enough and his team is smart enough to know that Mr. Gaetz will never be confirmed by the Senate. Anyway,” Miller said.

ABC News’ Rachel Scott, Lauren Peller and Isabella Murray contributed to this report.