Two transgender men are suing Kansas over a new law that invalidated their driver’s licenses and about 1,700 others for reflecting people’s gender identities and not their sex assigned at birth, arguing that the measure is “dehumanizing”.

The men filed their case Thursday, the same day the law took effect, and argue that it violates rights to privacy, personal autonomy and due legal process guaranteed by the Kansas state constitution. The men also are challenging the law’s tough, new enforcement provisions for the state’s three-year-old policy of barring transgender people from using public restrooms or other single-sex facilities associated with their gender identities.

The men are asking Catherine Theisen, Douglas county’s district judge, to block the law, which also invalidated about 1,800 transgender people’s birth certificates. The county is home to the main University of Kansas campus and is a liberal bastion in a generally conservative state.

“The Kansas constitution prohibits the Kansas legislature’s targeting of transgender individuals for this discriminatory and dehumanizing treatment,” the lawsuit says.

The state supreme court declared in 2019 that the Kansas bill of rights confers and protects a right to bodily autonomy – a decision that protected abortion rights.

The new law was enacted on 18 February when Republicans, who hold a supermajority in the legislature, overrode a veto by Democratic governor Laura Kelly. She appointed Theisen to the bench in 2022.

A 2023 state law, also enacted over Kelly’s veto, defined male and female by a person’s “biological reproductive system” at birth. The Kansas supreme court hasn’t yet reviewed it.

The law enacted more recently calls for stiff fines for cities, counties, public schools and state agencies that don’t restrict transgender people’s use of facilities, as well as fines and criminal prosecutions for transgender people who violate it. People can also sue trans individuals over alleged violations.

Republican legislators argued that the new law will protect girls and women and often described transgender women and girls as male.

“Kansans expect clarity, not confusion,” statehouse speaker Dan Hawkins, a Wichita Republican, said after the law was enacted. “They expect leadership, not surrender to radical activists.”

The law bars any “sex” listing on driver’s licenses and birth certificates other than the one assigned at birth and invalidates existing records that don’t comply. The state has started notifying transgender people by mail that their licenses are invalid and they must get new ones immediately.

At least eight other states don’t allow transgender people to change one or both documents – but only Kansas has invalidated documents that were previously changed.

The two men suing over the new law are from Lawrence – about 40 miles (64km ) west of Kansas City – and represented by American Civil Liberties Union attorneys. They’re identified as Daniel Doe and Matthew Moe, saying they fear discrimination, harassment and violence if they don’t remain anonymous.