The U.S. Supreme Court has declined to hear a lawsuit challenging the U.S. National Security Agency’s collection of U.S. phone records filed by a conservative activist, despite a lower court’s ruling that the program may be illegal.

The court, without comment, denied the request by activist and former federal prosecutor Larry Klayman, along with Charles and Mary Strange, to immediately hear their case against U.S. President Barack Obama, U.S. Attorney General Eric Holder, NSA Director Keith Alexander, Verizon Communications and Roger Vinson, the judge who signed the order allowing the surveillance.

Klayman had appealed the case directly to the Supreme Court after Judge Richard Leon of the U.S. District Court for the District of Columbia stayed his decision suspending the NSA program, pending appeal by the government.

The case has generated significant attention, with Leon ruling in December that the NSA’s large-scale telephone records collection program likely violates the U.S. Constitution.

Leon wrote that the plaintiffs’ reasonable expectation of privacy may be violated when the government “indiscriminately collects their telephone metadata along with the metadata of hundreds of millions of other citizens without any particularized suspicion of wrongdoing, retains all of that metadata for five years, and then queries, analyzes, and investigates that data without prior judicial approval of the investigative targets.”

Obama has since talked about ending the phone-records collection program, and several lawmakers have backed legislation that would end the program, but it remains in effect.

The DOJ declined to comment on the Supreme Court’s decision.

Klayman, founder of Judicial Watch, did not immediately respond to a request for comments on the Supreme Court’s decision. The Stranges are parents of Michael Strange, a Navy SEAL who was killed when his helicopter was shot down by Taliban fighters.