Some powerful political figures are calling for an apology.
House Speaker Paul Ryan called for the candidate to offer an apology.
RELATED: Montana GOP hopeful charged with misdemeanor assault against Guardian reporter
Greg Gianforte, who is running for an open House seat in Montana, is accused of body slamming a reporter. He blames the reporter for using "aggressive tactics." But the reporter thinks a recording of the incident will show what really happened.
The sound of the confrontation was captured by Guardian reporter Ben Jacobs.
Gianforte: I'm sick and tired of you guys.
Gianforte: The last guy that came in here did the same thing. Get the hell out of here. Get the hell out of here. The last guy did the same thing. Are you with the Guardian?
Jacobs: Yes and you just broke my glasses.
Gianforte: The last guy did the same damn thing.
Jacobs: You just body slammed me and broke my glasses.
Gianforte: Get the hell out of here.
On "Good Morning America," Jacobs said he was trying to ask Gianforte a question about healthcare.
"I went from being vertical one moment to being horizontal the next," he said.
His campaign blames Jacobs, saying in a statement, "The candidate was merely grabbing for the phone that he says Jacobs pushed in his face," adding "It is unfortunate that this aggressive behavior from a liberal journalist created this scene at our campaign volunteer BBQ."
A Fox News reporter in the room at the time setting up to interview Gianforte confirms Jacobs' account of what happened.
"I saw the whole thing when he grabbed him by the neck with both hands, slid him to the side. Body slammed him and got on top of him and started punching and yelling at him," the reporter said.
It's unclear how it will affect the race, since about two-thirds of voters in that state have already picked Gianforte in early voting ahead of Thursday's election.
But Republicans would still face a major decision whether or not to seat him.