A federal judge on Thursday denied disability rights advocates’ request to block an Illinois law going into effect this weekend that lets terminally ill patients obtain prescription medication to end their lives.

The ruling came in a federal lawsuit filed earlier this year by two disabled patients, a doctor and several disability and patients’ rights organizations. They allege the state’s End-of-Life Options for Terminally Ill Patients Act violates the Americans with Disabilities Act, which bars discrimination against people with disabilities; the Affordable Care Act, which regulates healthcare costs; and the plaintiffs’ equal protection under the 14th Amendment.

But in his 25-page decision, U.S. District Judge John J. Tharp rejected at least one of the plaintiffs’ arguments calling for a preliminary injunction to put the law on hold, disagreeing that doctors “will start inviting disabled patients to consider medical aid in dying” once the law takes effect.

“The Act exempts healthcare professionals from any duty to provide aid-in-dying care, states that a healthcare provider ‘may choose not to engage in aid-in-dying care,’ and provides that ‘only willing healthcare professionals shall provide aid-in-dying care in accordance with the Act,” Tharp wrote. “With this amount of discretion afforded to doctors, (one of the plaintiffs) cannot establish an immediate, imminent risk that all doctors will start inviting disabled patients to consider medical aid in dying.”

The law takes effect Saturday. The lawsuit will continue, though Tharp dismissed Gov. JB Pritzker as a defendant. Plaintiffs now have 30 days to show why the rest of the suit shouldn’t be dismissed as well.

Illinois joined at least 10 other states and Washington, D.C., in permitting medical aid in dying when Pritzker signed the law late last year. Pritzker said it would help terminally ill patients “avoid unnecessary pain and suffering at the end of their lives.”

Opponents call the law immoral because it lets patients choose to end their lives. Other legal challenges are pending, including one filed last week by Cardinal Blase Cupich, the archbishop of Chicago, and other clergy.

Tribune reporter Jason Meisner contributed.