PITTSBURGH  Six groups that want to demonstrate during the Group of 20 summit meeting here on Sept. 24-25 filed a federal lawsuit Friday claiming they were being denied the right to protest.

The groups, which engage in a wide array of social justice advocacy, have been talking for over a month with the defendants  the city, the Secret Service and the Pennsylvania Department of Conservation and Natural Resources  about logistics surrounding demonstrations.

But only 2 of 13 permits sought have been granted, and those are for events that will be held either outside the downtown area, where leaders of 20 of the world’s largest and emerging economies are to gather, or before the meeting, the lawsuit asserts.

“What they’re essentially doing is refusing permits for any demonstration in downtown Pittsburgh, and that’s unprecedented,” said Witold Walczak, a lawyer for the American Civil Liberties Union of Pennsylvania, which is representing the six plaintiffs: Codepink, the 3 Rivers Climate Convergence, the Thomas Merton Center, Pittsburgh Outdoor Artists, Bail Out the People and G-6 Billion.