A joint UT/Texas Tribune poll released Monday shows a close gubernatorial race shaping up between Greg Abbott, the likely Republican nominee and state attorney general, and state Sen. Wendy Davis, D-Fort Worth, the likely Democratic candidate.

The poll, which is Texas’ only statewide, open-source public opinion survey, lists Abbott in the lead with 40 percent of likely voters and Davis trailing behind with 34 percent. But in the case of a three-way race between Abbott, Davis and the Libertarian gubernatorial-hopeful Kathie Glass, Glass would net 5 percent of the vote, with Abbott’s share of the vote unchanged and Davis’ totaling 35 percent, according to the study.

Jim Henson, director of the Texas Politics Project and co-director of the poll, emphasized that he thinks it is too early to read the poll as a definitive statement about how things will turn out on election night. Discussing Glass’ effect on the election outcome, he noted that Libertarian candidates typically attract voters who would otherwise vote Republican, but it is not yet clear how much that will affect the race.

“Just how critical that effect will be will depend on how the campaigning unfolds,” Henson said.

In June, the UT/Texas Tribune poll found that 58 percent of likely voters had no opinion on Wendy Davis, compared with only 16 percent in Monday’s poll.

“When you look at the favorable and unfavorable numbers for Abbott and Davis, you see that many more people have opinions about Davis than they did in June,” Henson said. “In June, almost no one knew who she was.”