Democratic Rep. Keith Ellison has fallen behind Republican Doug Wardlow in the race for Minnesota attorney general, a new poll released this week showed.

Wardlow flipped the race on its head, pacing Ellison by 7 points, 43 percent to 36 percent, according to the Star Tribune/MPR News poll conducted as the discussion surrounding an allegation of domestic abuse levied against Ellison by his ex-girlfriend heightened over the last month.

Ellison has forcefully denied the claim. His ex-wife has also taken the Democratic congressman’s side, saying that even though their relationship ended in a messy divorce, Ellison never struck her and is not the type of person to turn physically violent on a woman.

Roughly one in six of the 800 likely voters surveyed from Oct. 15 through Oct. 17 remained undecided, a considerable bloc this late in the race.

Wardlow’s lead is on the fringe of the survey’s margin of error of plus or minus 3.5 percentage points.

Ellison, the deputy chairman of the Democratic National Committee, led Wardlow by 5 points in a similar poll in September.

But the ongoing dispute over the assault allegation from his ex-girlfriend, Karen Monahan, appears to have rankled his campaign, even though Monahan has declined to turn over a video she says she has of Ellison pulling her off his bed by her feet and screaming profanities at her.

Ellison has said such a video could not possibly exist because the alleged event never took place.

He has called for a House Ethics Committee probe into Monahan’s allegation so that he can clear his name.

“I am taking this step now because I am innocent and eager to see this entire matter resolved,” the Minnesota Democrat said in a statement last month.

The state Democratic party hired an outside counsel to investigate Monahan’s claim. That investigator concluded that the claim was “unsubstantiated” because Monahan “claims to possess evidence that could conclusively corroborate her allegation as well as potentially answer all of the questions surrounding it, if it occurred,” but has instead “chosen to withhold that evidence.”