Arizona would ban female transgender students from competing in female sports under a bill that already has gained significant support from Republican lawmakers at the Capitol.

Rep. Nancy Barto, R-Phoenix, argued her "Save Women's Sports Act" is a matter of fairness for female athletes.

But LGBT rights groups contend similar measures in states around the country are designed to discriminate against transgender young people and whip up a culture war-style political debate.

Under House Bill 2706, interscholastic and intramural leagues would have to designate sports as co-educational, male or female — based on what the law terms "biological sex." Teams or sports designated as "female" would be closed "to students of the male sex."

The restrictions would apply at both public and private schools, including community colleges and universities.

A student could challenge their designation as male by getting a sworn doctor's statement detailing the student's genetic makeup, "internal and external reproductive anatomy" and "normal endogenously produced levels of testosterone."

Barto's proposal also would allow students to sue a school if they believe they were harmed by a violation of her law.

"Female student-athletes should not be forced to compete in a sport against biological males, who possess inherent physiological advantages. When this is allowed, it discourages female participation in athletics and, worse, it can result in women and girls being denied crucial educational and financial opportunities," Barto said in a statement.

The lawmaker, who is running in a competitive Republican primary for the state Senate, did not respond to requests for an interview Friday.

Twenty-two Republicans in the House of Representatives already have signed on as co-sponsors of the bill.

The bill is similar to legislation filed in several other states this year seeking to keep transgender students out of girls' sports. Some of the measures are backed by Scottsdale-based Alliance Defending Freedom.

A press release from Barto about her bill did not include examples of transgender athletes creating the problems she described, in Arizona or elsewhere.

Opponents see bill as way to 'divide people'

"There's a reason these bills are popping up simultaneously," said Shannon Minter, legal director for the National Center for Lesbian Rights. "There have been no problems with this issue in Arizona. This isn't responding to an issue that students are having in Arizona. This is a national campaign to use this issue — sadly — to just polarize and divide people."

The bill is the latest flavor of the "bathroom bills" introduced in legislatures around the country over the last few years, Minter said.

"This is just about attacking transgender kids for political reasons," Minter said.

Arizona's current policy is humane and reasonable, he said.

The Arizona Interscholastic Association approved the first transgender student-athletes to compete in the state in 2014.

Officials have said that they receive few requests, however.

The organization's current process requires transgender athletes to compile letters of support from parents, a school administrator and a qualified health professional. They must then get approval from a committee as well as the association's executive board.

Contact Andrew Oxford at andrew.oxford@arizonarepublic.com or on Twitter at @andrewboxford.