The public interest group Consumer Watchdog doesn’t have standing to challenge the U.S. Patent and Trademark Office’s decision to uphold a patent on human embryonic stem cells, according to a ruling Wednesday by the U.S. Court of Appeals for the Federal Circuit.

The decision will affect public interest organizations such as Consumer Watchdog and the Electronic Frontier Foundation, which have challenged patents they oppose on policy grounds. While they can continue to lodge challenges at the Patent Trial and Appeal Board in the PTO, they won’t be able to appeal an adverse decision to the Federal Circuit.

Consumer Watchdog, represented by Public Patent Foundation executive director Daniel Ravicher, tried unsuccessfully to convince the PTO in 2006 to invalidate claims on the cell stem patent owned by Wisconsin Alumni Research Foundation. That decision was made before the U.S. Supreme Court ruled in another case—Association for Molecular Pathology v. Myriad Genetics—that patents can’t be issued for isolating genes that are found in nature.

Judge Randall Rader, who recently stepped down as chief judge amid an ethics controversy, wrote Wednesday’s opinion. The new chief judge, Sharon Prost, was also on the panel, along with Judge Todd Hughes. During oral arguments, Rader questioned Ravicher on whether his client, a third party that has not suffered direct harm as a result of the patent, had standing.

Ravicher argued that his client has standing because the 2011 America Invents Act allows anyone, including a person who is not the owner of a patent, to seek review through the PTO’s appeal process. The law also allows the losing party in this process to appeal, he said.

The panel disagreed, finding that a statutory grant of a right to appeal does not eliminate the standing requirements of Article III of the Constitution. “Because Consumer Watchdog has not identified a particularized, concrete interest in the patentability of the ’913 patent, or any injury in fact flowing from the board’s decision, it lacks standing to appeal the decision affirming the patentability of the amended claims,” Rader wrote.

The panel asked the PTO and the U.S. Department of Justice to weigh in on the dispute, and both took the position that Consumer Watchdog lacked standing.

Steptoe & Johnson intellectual partner partner Thomas Filarski said it’s unclear how far the panel’s reasoning will extend. “By requiring this patent challenger to establish standing to appeal through injury in fact, has the Federal Circuit headed down a slippery slope of conflict with the intent Congress had by enacting the [America Invents Act]?” he said.

Ravicher said in an email that Consumer Watchdog is disappointed and will consider its options, including the possibility of filing a certiorari petition with the U.S. Supreme Court.