Advocates have already filed a lawsuit to block a new rule that would shield skilled care employees against acts that violate their religious principles.

Both the San Francisco city and county filed suit against the Dept. of Health and Human Services Thursday, the same day that the new “Conscience Rule” was finalized. Opponents are worried the rule — which allows providers and institutions to opt out of assisted suicides, executing problematic advanced directives, or carrying out vaccinations — will only fuel discriminatory healthcare practices.

The Human Rights Campaign, the National Center for Lesbian Rights and Fenway Health were among the organizations Thursday expressing concern that the rule would allow providers to deny care to lesbian, gay, bisexual and transgender individuals.

“We won’t go back to the days when Americans seeking healthcare faced discrimination simply because they were female or LGBTQ,” California Attorney General Xavier Becerra said in a statement.

San Francisco’s lawsuit called the rule “unconscionable and unlawful,” and asks the U.S. District Court for the Northern District of California to strike it down “in full.”

Administration officials, meanwhile, emphasized that no new law was created Thursday, and the final rule replaces a 2011 version that had proven inadequate. The Conscience Rule implements 25 provisions passed by Congress previously to protect workers’ religious freedom on the job. Others applauded the announcement last week.

“The new rule is a victory for common sense and religious diversity. We need more healthcare in this country — not less. We all win if nurses, doctors and other healthcare professionals can heal others without fear of being forced from their life’s work because of their religious beliefs,” said Montse Alvarado, VP and executive director of Becket, a law firm that has represented the Little Sisters of the Poor in a fight over contraceptive mandates.