PHOENIX — Arizona lawmakers have jumped in to the national debate over the rights of transgender people with a bill being debated Wednesday that would make it illegal for people to use public restrooms not associated with their birth gender.

Advocates said the measure would be the toughest standard in the nation for transgender people and bathroom use, requiring Arizona residents to use the restroom of the sex listed on their birth certificate. One local TV station has dubbed it the “Show Me Your Papers Before You Go Potty” bill, a reference to the Arizona Legislature’s sweeping 2010 immigration law.

State and local governments are increasingly adding gender identity to anti-discrimination bans to ward off legal battles, but the delicate issue of what kind of restroom can be used by men and women of a gender other than what they were born as remains largely unexplored, despite a growing number of people identifying as transgender.

Transgender people have successfully sued businesses that didn’t provide equal access to public facilities under state and local anti-discrimination bans that include gender identity.

But opponents and proponents alike complain that the laws don’t explicitly demand businesses provide equal access for transgender people, creating confusion over how governments, restaurants, clothing stores and other establishments must act.

In recent weeks, Massachusetts and California took steps to clarify such laws and ensure equal access for transgender students to gender-segregated facilities. Phoenix passed a human-rights ordinance last month prohibiting gender-identity discrimination at public accommodations.

“If you look like a man and you live your life like a man, you should be able to use a man’s bathroom,” said Dru Levasseur, a transgender rights attorney for Lambda Legal, a national gay advocacy group based in New York. “It’s just common sense.”

In Arizona, where Republicans control state government, GOP Rep. John Kavanagh said he was outraged by Phoenix’s effort to increase protections for transgender people. His proposed law would make it a misdemeanor for a person to use a public restroom, bathroom, shower, bath, dressing room or locker room associated with a gender other than what is on his or her birth certificate.

Penalties include the possibility of six months in jail.