TEXAS (CBSDFW.COM) – Gov. Greg Abbott signed a bill into law restricting Texas’ transgender student-athletes from playing on K-12 school sports teams that align with their gender identity.

House Bill 25, authored by state Rep. Valoree Swanson, R-Spring, will require student athletes who compete in interscholastic competition to play on sports teams that correspond with the sex listed on their birth certificate at or near their time of birth. It goes into effect Jan. 18.

READ MORE: Mesquite Officer Dies After Shooting Outside Grocery Store

“I’m excited that we have the opportunity today to stand up for our daughters, granddaughters, and all our Texas girls,” Swanson told CBS 11.

There are more than 800,000 7th through 12th grade athletes in public schools in Texas, including more than 300,000 girls.

Swanson said if transgender girls are allowed to compete with girls, they would have a competitive advantage. “It also makes it where they have absolutely no opportunity, they know that it’s already set, the results are already set before they even start.”

But opponents, including Representative Julie Johnson of Farmers Branch, said there isn’t a problem in Texas with transgender athletes.

READ MORE: Fort Worth ISD Hopes To Hire Teachers 'On The Spot,' Offering Huge Incentives

“How can you say that girls are being unfairly positioned in competition in the state of Texas such to justify this bill that there has not been a single complaint, not a single complaint to the UIL about transgender athletes being able to compete?”

Johnson and others have said debate over this and similar bills for the past ten months has led to a sizable increase in phone calls by transgender students to a suicide hotline.

The Trevor Project said it received nearly 4,000 crisis contacts from transgender and nonbinary youth in Texas this year.

Leslie McMurray, a transgender woman who advocates for others at the Dallas Resource Center, is among those watching debate over the bill about public school athletes.

“This legislature has been all about attacking children, I don’t understand it. I think it’s reprehensible. If you have a girl who’s respected as a girl, treated as a girl in all of her classrooms and by her friends and every other way until she steps on the playing field, when suddenly she’s treated like a boy, that’s not right.”

MORE NEWS: Delivery Drones Buzzing Over Some North Texas Cities

The legislation goes further than current rules from the University Interscholastic League, which governs school sports in Texas. Under current UIL rules, a student’s gender is determined by their birth certificate. But UIL also accepts legally modified birth certificates in which someone may have had their sex changed to align with their gender identity.

CBSDFW.com Staff