A congressional hearing degenerated into an angry confrontation between a senator and a witness on Tuesday after Republican Senator Markwayne Mullin of Oklahoma challenged the head of the Teamsters union to stand up and resolve long-standing differences on the spot.

Sen. Bernie Sanders of Vermont, the chairman of the Senate panel that held the hearing, yelled at Mullin to sit down after challenging Sean O’Brien to a fight. Mullin had risen from his seat on stage and appeared to remove his ring.

This is the time, this is the place, Mullin told OBrien after reading a series of critical tweets the president of the International Brotherhood of Teamsters had sent about him in the past. If you want to talk, we can be two consenting adults. We can finish it here.

The two men never came face to face in the interrogation room. But they hurled insults at each other for about six minutes as Sanders repeatedly banged his gavel and tried to cut them off.

You are a United States Senator! Sanders yelled at Mullin at one point.

Sanders, a longtime union ally, argued with Mullin and O’Brien to focus on the economic issues that were the subject of the Senate Health, Education, Labor and Pensions Committee hearing, which Sanders held to assess how unions help working families.

A new rule would make it easier for millions of Americans to join a union, but companies are pushing back

Mullin, a frequent critic of union leadership, has spoken with O’Brien before. Earlier this year, O’Brien repeatedly posted about Mullin on X, formerly Twitter, calling him an idiot and full of s after Mullin criticized O’Brien at a hearing for what Mullin said were intimidation tactics.

In another social media post, which Mullin read during Tuesday’s hearing, OBrien appeared to challenge Mullin to a fight. You know where to find me. Anywhere, anytime, cowboy, O’Brien had posted.

The exchange escalated from there, with Mullin telling OBrien that this was the spot and asking if he wanted to do it right now.

I’d like to do it now, OBrien said.

As workers’ actions continue, the White House is highlighting how the government is helping unions

Mullin replied: Well, get up then.

You stood with your butt up, O’Brien shot back.

When Mullin rose from his chair and appeared ready for a fight, Sanders yelled at him to sit down, banged his gavel several times and told both of them to stop talking.

This is a hearing, and God knows the American people have enough contempt for Congress, let’s not make it worse, Sanders said.

As Mullin persisted, OBrien responded: You challenged me to a cage match and acted like a 12-year-old schoolyard bully.

The two exchanged angry insults for several more minutes, at one point calling each other a thug along with Mullin, suggesting they would fight at a charity event next spring, repeating an offer he made earlier this years on social media.

O’Brien declined, instead suggesting they meet for coffee and work out their differences. Mullin accepted, but the two continued to yell at each other until the next senator, Maggie Hassan (D-N.H.), began her questioning by talking about them.

Sanders called the exchange absurd after the hearing.

Enemy Kevin McCarthy accuses former speaker of ‘sucker punch’ elbow in Capitol hallway

We were there to talk about the crisis facing working families in this country, the growing gap between the very rich and everyone else, and the role that unions play in improving the living standards of the American people. , Sanders said. We’re not here to talk about cage fighting.

When later asked about the skirmish, Senate Republican leader Mitch McConnell of Kentucky objected. It is very difficult to control the behavior of everyone in the building, McConnell said. I don’t see that as my responsibility.

Sen. Kevin Cramer (R-N.D.) said the back-and-forth was referenced during a GOP conference after the hearing. But he said no one should take it too seriously.

It is a dynamic place,” Cramer said of the Senate. “We don’t wear the white wigs anymore.