Republican senator Rand Paul’s son William apologized on Wednesday for a drunken tirade at a bar in Washington DC, in which he reportedly told a Republican congressman he “hates Jews and hates gays”.

“Last night, I had too much to drink and said some things that don’t represent who I really am. I’m sorry and today I am seeking help for my drinking problem,” William Paul posted on social media under the handle TastyBrew1776.

The apology was posted minutes after Mike Lawler, a Republican congressman, told reporters the senator’s son had drunkenly accosted him on Tuesday night at a bar and said he would hold “anti-American” Jews responsible if his father’s ally, Thomas Massie, a Kentucky congressman, loses a primary election next week.

The younger Paul, who recently served as a congressional aide to two of Lawler’s Republican colleagues in the House, went on “a 10-minute diatribe about Jews” at the Tune Inn Restaurant & Bar on Pennsylvania Avenue, Lawler said, and “said that he hates Jews and hates gays and doesn’t care if they die”.

“I think that’s fucking disgusting,” Lawler said.

Details of the incident were first reported earlier on Wednesday by a witness, Reese Gorman of the digital publication Notus, in a remarkable first-hand account.

Lawler told the New York Post that Paul also blamed Israel for the US war on Iran, and said the US was “trying to steal Iran’s land for the Jews and steal the West Bank”.

Rand Paul’s senate office did not immediately return the Guardian’s request for comment.

Massie is engaged in an increasingly bitter and nasty primary campaign against Ed Gallrein, a former navy Seal who is endorsed by Donald Trump and backed by Republican billionaire donor Paul Singer, who is Jewish and supports gay rights.

Massie, a critic of the US-Israel war on Iran, enraged the president by leading the effort to force the release of files on Jeffrey Epstein, the late sex offender Trump socialized with for nearly two decades.

As Axios has reported, an outside group supporting Massie’s campaign focused on Singer in a recent ad attacking Gallrein. “Eddie Gallrein is bought and paid for by the LGBTQ mafia,” the ad begins. “Far-left trans activist billionaire Paul Singer is bringing his trans madness to Kentucky. Singer is spending millions to remove Massie. The gay mafia will own woke Eddie.” The ad features an image of Singer in front of a rainbow-colored Star of David.

William Paul, who has been charged multiple times for drunken assault or driving in the past, reportedly told Lawler: “Paul Singer serves Israeli interests, not American interests.”

After Lawler pointed out that he was not Jewish, Paul, who confessed that he was drunk, allegedly said: “Oh wow, I’m so sorry for calling you a Jew,” before launching into the tirade. He then urged Lawler “to watch more Tucker Carlson”, before reportedly flipping off the congressman and tripping over his bar stool as he left.

William Paul’s LinkedIn profile indicates he spent part of last week in San Diego, attending a conference with the Christian Employers Alliance. His profile photo on the social network shows him pointing approvingly at a statue of Barry Goldwater, whose grandfather was an Orthodox Jew, in the US Capitol.