BOISE — The Idaho Senate voted along party lines Tuesday evening to ban transgender people from changing their sex on their birth certificates to match their gender identity.

The 27-6 vote sends the bill, which has already passed the House, to Gov. Brad Little's desk. Transgender Idahoans have been allowed to change their birth certificates since 2018 due to a federal court ruling, and the bill, if it becomes law, will almost certainly land the state back in court.

"We know that we are boys and girls from a very young age," said Sen. Lee Heider, R-Twin Falls. "We are men and women on this floor, and nothing changes that."

Rep. Julianne Young, R-Blackfoot, sponsored the bill in the House. Its supporters said the state has an interest in maintaining accurate statistical information about the state's residents, including gender at birth.

“Biological sex is not interchangeable with gender identity,” said Sen. Mary Souza, R-Coeur d’Alene. “They are totally and completely different things.”

Senate Minority Leader Michelle Stennett, D-Ketchum, said the bill is “an intentional violation of the law,” pointing to an opinion from the state Attorney General’s office saying the bill could lead to expensive litigation.

“It is incredibly unconscionable to treat our citizens this way,” she said.

Lamba Legal, the pro-gay rights group that represented the plaintiffs in the 2018 lawsuit, urged Little to veto the bill.

“Idaho lawmakers might as well try to tear down the federal courthouse if they have this much contempt for the rule of law,” said Peter Renn, a member of the legal team that obtained the 2018 court ruling. “They are explicitly defying a court order and exposing Idaho taxpayers to footing the bill for significant financial consequences — all while putting transgender people back in harm’s way for harassment and even violence, and once again making Idaho a national outlier. While the rest of the world is on fire responding to our global health crisis, Idaho lawmakers are fixated on transgender people’s birth certificates and coming up with solutions in search of problems."

Another bill that would still let transgender adults change their birth certificates using the current process but would require a medical attestation for a minor is pending in the Senate and hasn't gotten a vote yet.

The House also voted Tuesday to agree to the Senate's amendments to a bill to ban transgender girls and women from playing on female high school and college sports teams. That bill, which is being sponsored by Rep. Barbara Ehardt, R-Idaho Falls, needs to come to another vote in the House before it can head to Little's desk.

Reporter Nathan Brown can be reached at 208-542-6757. Follow him on Twitter: @NateBrownNews.