WASHINGTON (AP) — Rep. Matt Gaetz said Monday he will not leave Congress and denied that he "slept with" an underage girl, suggesting that accusations against him stem from political foes angry that he "loathes the swamp."

The Florida Republican, starting his fifth year in Congress, has been battling to preserve his political career since reports last week that he is under federal investigation for possible sex crimes. In a column in the Washington Examiner, a conservative news outlet, Gaetz predicted that "some of my feckless colleagues in Congress" will call for him to step down.

"No, I am a...