A federal judge on Tuesday cleared the way for a landmark California law that bars a controversial therapy aimed at reversing homosexuality in children and teenagers to take effect in January.

California's Democratic Governor Jerry Brown signed the ban into law in September, making the nation's most populous state the first to ban so-called conversion therapy among youths.

U.S. District Court Judge Kimberly Mueller denied an injunction request against the law filed by the National Association for Research and Therapy of Homosexuality and the American Association of Christian Counselors, as well as unnamed individuals who sued shortly after the law was signed.