TOPEKA, Kan.—A Kansas bill banning transgender athletes from girls’ and women’s sports was vetoed by Democratic Gov. Laura Kelly for the third year in a row Friday, setting up a hotly contested fight in the Republican-controlled Legislature to override her.

Kelly’s action was expected because of her two previous vetoes. Kansas Republicans made Kelly’s vetoes a major issue in multiple television attack ads when she ran for reelection last year, winning narrowly.

The governor said in her veto message that the bill would harm students’ mental health and hurt the state’s efforts to recruit businesses. Kelly also said lawmakers should leave the issue to the state association set up decades ago to run student activities in middle and high schools.

“Let’s be clear what this bill is all about—politics,” Kelly wrote. “It won’t increase any test scores. It won’t help any kids read or write. It won’t help any teachers prepare our kids for the real world.”

Kelly’s arguments Friday were similar to those she made in past veto messages and during her reelection campaign.

Republicans have more than the two-thirds majorities in both chambers needed to override a veto, but in 2021 and 2022, a few GOP moderates voted against overriding Kelly. The House and Senate votes on this year’s bill suggest supporters could have just enough votes to prevail.

“Despite her repeated pledges to meet us in the middle, the governor has decided to side yet again with the most radical elements of her party,” Kansas Senate President Ty Masterson, a Wichita-area Republican, said in a statement Friday.

The measure would apply to girls’ and women’s K-12, club and college sports. If supporters can override Kelly’s veto, Kansas would join 18 other states with such a law, including Iowa, Oklahoma, and Texas.