Colorado is weighing in on a legal battle against Idaho’s new law restricting a minor’s ability to cross state lines to receive an abortion.

Colorado Attorney General Phil Weiser filed a brief Monday in support of a lawsuit challenging Idaho’s law, which makes it a crime for adults to help minors obtain abortion pills, or for a minor to leave the state for abortion care without parental permission. 

Weiser argued that Idaho’s law is unconstitutional, joining attorneys general from 18 other states and Washington D.C. in the brief. Weiser said Idaho should not be able to criminalize conduct that is legal in other states and urged the U.S. District Court to block Idaho’s law. 

“Idaho’s law is vague and unclear, and it infringes on constitutional rights to travel and speech,” Weiser said. “States cannot prevent their residents from accessing safe abortion care in other states where it is legal nor can they prevent doctors from sharing truthful information with their patients about such lawful care.” 

The brief argues that Idaho’s law endangers the health of minors, punishes other states’ medical providers, and floods Idaho’s neighboring states with residents seeking abortion care. 

Idaho shares a border with Oregon and Washington, where minors can legally obtain abortion care without parental consent.

For residents of southeast Idaho, Colorado is the nearest state for abortion access, with a roughly four hour drive separating the states at their closest points. Colorado requires parental notification for minors to receive abortions, but not parental consent. The notification requirement can also be waived in circumstances including child abuse, child neglect or medical emergencies. 

“I am committed to protecting patients’ right to travel to Colorado and doctors’ ability to practice medicine,” Weiser said. 

Colorado is among the strongest states in the nation for abortion protections. Since April, a new state law also shields Colorado abortion patients and providers from out-of-state penalties. The law prohibits Colorado from recognizing criminal prosecutions or civil lawsuits regarding legally protected abortion care and directs state agencies to withhold relevant records from such states. 

This is the third time Colorado has gotten involved in challenging Idaho’s abortion restriction laws. 

Within the last year, Colorado has joined briefs in support of lawsuits against Idaho laws that were interpreted to prohibit providers from making out-of-state referrals for abortion care, and inflict criminal penalties on doctors who provide abortion-related medical care in life-threatening emergency situations.

The other attorneys general who signed onto Monday’s brief represent Arizona, California, Connecticut, Delaware, Hawaii, Illinois, Maine, Maryland, Massachusetts, Minnesota, Nevada, New Jersey, New Mexico, New York, North Carolina, Oregon, Rhode Island, Washington and Washington D.C.