Kentucky Governor Andy Beshear, a Democrat, on Wednesday vetoed a bill that sought to prohibit transgender girls from competing on sports teams consistent with their gender identity.

Beshear is the third governor after GOP governors in Utah and Indiana to veto such a bill.

In his veto letter, Beshear said that the bill was unnecessary because guidelines are already being implemented by the Kentucky High School Athletic Association (KHSAA).

“Under the KHSAA policy, a student-athlete cannot compete if they have an unfair advantage," Beshear said. "The KHSAA policy requires that a student-athlete who has undergone sex reassignment after puberty must take hormonal therapy in a verifiable manner and for a sufficient length of time to minimize gender-related advantages in competition."

Beshear added that Senate Bill 83, titled the Fairness in Womens' Sports Act, “most likely violates the equal protection rights afforded by the United States Constitution because it discriminates against transgender children seeking to participate in girls' or womens' sports.”

The Human Rights Campaign (HRC), the nation's largest LGBTQ rights advocate, said that the governor had done “the right thing” by vetoing the bill and called on lawmakers not to override his veto.

“Governor Beshear did the right thing today vetoing this bill – a bill that would only cause problems, not solve them, by singling out Kentucky’s transgender children for exclusion and discrimination in their own schools,” said HRC State Legislative Director and Senior Counsel Cathryn Oakley. “With the well-being of transgender youth in the balance, Governor Beshear lived up to Kentucky values and to his catchphrase ‘Team Kentucky.’”

“We urge lawmakers to uphold the veto because transgender children, like all Kentucky children, deserve better than being treated as political pawns – what they deserve is to be able to have fun with their friends, exercise, and learn how to be part of a team. This veto is a strong statement of Kentucky values and the legislature must allow it to stand,” Oakley added.

GOP state lawmakers passed the measure with veto-proof majorities.