A federal judge on Monday blocked a Trump administration rule requiring drugmakers to put prices in television ads, a central part of the president’s push to lower the cost of prescription medications.

The decision from U.S. District Judge Amit Mehta in Washington, D.C., is the latest blow to a number of administrative actions on health care. Judge Mehta sided with drug companies, saying the Health and Human Services Department rule would violate free speech and exceeded the agency’s statutory authority.

“But no matter how vexing the problem of spiraling drug costs may be, HHS cannot do more than what Congress has authorized,” he wrote in his decision. “The responsibility rests with Congress to act in the first instance.”

The lawsuit was brought by three pharmaceutical companies: Merck & Co. , Eli Lilly & Co. and Amgen Inc.

The rule, completed in May, was part of President Trump’s broader blueprint to lower drug prices and was set to go into effect Tuesday. It required list prices to be included in direct-to-consumer TV ads for most prescription drugs covered by Medicare and Medicaid. The ruling blocks the rule from going into effect.