AUSTIN, Texas — The Texas Supreme Court allowed a new state law banning gender-affirming care for minors to take effect on Friday, setting up Texas to be the most populous state with such restrictions on transgender children.

Legal advocates who sued on behalf of the families and doctors, including the American Civil Liberties Union, called the law and the high court’s decision Thursday “cruel.“

“Transgender youth and their families are forced to confront the start of the school year fearful of what awaits them. But let us be clear: The fight is far from over,” the advocacy groups said in a joint statement.

Last week, a state district judge ruled the pending law violated the rights of transgender children and their families to seek appropriate medical care, and violated doctors’ ability to follow “well-established, evidence-based” medical guidelines under threat of losing their license.

The judge issued a temporary injunction to block the law and state officials immediately appealed to the state’s highest court for civil cases.

The order from the all-Republican Supreme Court lifting the injunction and allowing the law to take effect did not explain the decision. The order did not address the lower court’s ruling that the law is unconstitutional, and a full hearing is expected.

More than 20 states have adopted laws to ban some gender-affirming care for minors, although some are not yet in effect or have been put on hold by courts.

Several Republican-led states have taken steps to bar access to gender-affirming care for transgender minors, which for people under 18 typically involves puberty blockers or other hormone treatments. Some Democratic-led states are instituting protections.