The U.S. Supreme Court on Monday left intact California's ban on gay conversion therapy, rejecting a Christian minister's challenge to the law over its perceived infringement of his religious rights.

This marks the third time in three years that the justices have turned away a challenge to the 2012 law, ruling that it neither impinged upon free exercise of religion nor impacted the activities of the clergy.

The law prohibits state-licensed mental health counselors from offering therapy to change the sexual orientation of minors. The Supreme Court refused to review the law in 2014 after an appeals court rejected claims that it infringed on the free speech rights secured under the U.S. Constitution's First Amendment.

California was the first state to ban conversion therapy in 2012, calling it ineffective and harmful. New Jersey, Illinois, Oregon, Vermont, New Mexico and the District of Columbia later followed suit.

Gay conversion therapy methods range from hypnosis, counseling and dating-skill training to dangerous techniques that induce pain or electric shocks in response to erotic images of same-sex couples. Such treatments stem from the belief that homosexuality is a mental illness, a view that has no basis in science and has been discredited for decades.

Lead plaintiff Donald Welch, an ordained minister and family therapist, manages counseling at Skyline Wesleyan Church, an evangelical congregation in San Diego.

Welch sued the state for its "unconstitutional law" alongside a Catholic psychiatrist and a man who underwent conversion therapy and now desires to perform it on others.

After a free speech challenge failed, the trio claimed the ban violated their right to freely exercise their religious beliefs. Last October, the San Francisco-based 9th U.S. Circuit Court of Appeals rejected their argument.