Susan Collins

U.S. Sen. Susan Collins and her likely Democratic challenger, Troy Jackson, are in a close race, though Jackson may have a slight edge, according to a new poll.

In a general election matchup between the two, 49% of likely voters would pick Jackson while 46% said they would pick Collins. Five percent said they were undecided or would select another candidate, according to the poll released Tuesday from the University of New Hampshire Survey Center.

The poll was completed by 1,236 Maine residents between July 15 and July 20, and had a margin of error of +/- 2.8%.

Jackson, a former lawmaker and president of the Maine Senate, is expected to secure the Democratic party’s nomination for the U.S. Senate race at a convention this weekend. His candidacy comes after Graham Platner, who won the Democratic primary in June, dropped out of the race earlier this month following an allegation of sexual assault, which he has denied.

This is a developing story.