Senator Jeanne Shaheen (D., N.H.) and Republican challenger Scott Brown continue to find themselves neck-and-neck in the New Hampshire Senate race less than four weeks away from the election.

The latest NH1/New England College poll shows Shaheen leading Brown 48.5 percent to 46 percent, falling within the roughly three-point margin of error. Just 3 percent of voters remain undecided at this point.

The candidates took part in a debate on Monday, in which they largely focused on foreign policy and women’s issues. The next day, Shaheen released an ad going after Brown’s position on abortion, which he called a “smear campaign” for misrepresenting his position as a pro-choice Republican.

In its poll last week, the outlet found both candidates tied at 47 percent.