PORTLAND — Occupy Maine is arguing that the state constitution provides the protestors in Lincoln Park with rights beyond those granted by the federal constitution.

The group filed its lawsuit against the city on Monday, arguing that rules about park usage and the City Council’s permit denial for the encampment violated the protestors’ rights. The suit was filed in Superior Court, where issues around both the federal and state constitutions can be addressed. It would be the first Occupy case to be decided under that state constitution.

Occupy Maine and the four individual plaintiffs in the suit are relying on the rights provided in the state constitution to defend their rights, John Branson, the group’s lawyer, said during a news conference on the back steps of the Cumberland County courthouse. Among the relevant sections of the state constitution he cited was one that provides people the right to consult upon the common good.

“If you don’t have the ability to maintain a sustained presence and community as they do in Lincoln Park, I don’t think that right means anything. If you have to clear out at 10 o’clock at night, you can’t have the kind of conversation that’s going on in Lincoln Park, which is one of the most amazing conversations I’ve ever been part of,” Branson said.

The filing allows the encampment to remain in place. Occupy Maine and city officials agreed that the protesters would not have to leave while the case is in litigation.

With their lawsuit, the protesters in Portland have joined the many Occupy groups that have taken their disputes to either federal or state court.

There’s no roughly comparable case to Occupy Maine’s because each case deals with particular municipal restrictions and possibly a specific state’s constitution, said Zachary Heiden, legal director of the ACLU of Maine Foundation. The organization filed a friend-of-the-court brief in support of Occupy Maine.

Heiden said while the federal constitution deals with the rights of Congress to restrict speech, Maine’s constitution speaks of the affirmative right of speech.

“Some justices of the Maine Supreme Judicial Court over the years have said maybe this is a stronger protection, this goes beyond what the federal constitution protects,” Heiden said. “We hope that’s what the courts will say in this case.”

Berney Kubetz, a Bangor-based lawyer with a specialty in First Amendment issues, said the state constitution is more affirmative than the federal, but he doesn’t believe it will provide a lot of traction to Occupy Maine.

“If I were representing the movement, I would probably cite it and suggest it goes way beyond the federal constitution in its grant of power to the people … But I don’t really see it having a lot of teeth a judge would grab on to and say, ‘Ah ha, this is the basis on which I would rule in favor of the movement,” he said.

Courts have been looking to a 1984 U.S. Supreme Court case — Clark v. Community for Creative Non-Violence — when considering Occupy cases, said Dmitry Bam, a professor at the University of Maine School of Law. In that case, the court found that protesters did not have the right to sleep in national parks and that the restriction was reasonable and not based on the content of the group’s activity.

Around the country, the Occupy movement has faced the challenge of showing that the restrictions they’ve faced are not content neutral, Bam said. That could require proving that the intent was discrimination.

“The ideal smoking gun would be an e-mail that says, ‘I’m tired of these people expressing their views or their anti-corporate views,'” he said. “You’re trying to find one of the exceptions to this old case to hang your hook on.”

In its complaint, Occupy Maine asserts that a municipal anti-loitering provision that prohibits people from Lincoln Park between 10 p.m. and 6:30 a.m. constitutes a blanket ban on speech and assembly during those hours. The group argues that the restrictions are inherently overly broad and that they are also applied unfairly to the protesters, whose expression relies on sustained, continuous assembly in a public space.

Another rule requiring advance permission for gatherings of more than 25 people or lasting more than three days is unconstitutional, the complaint argues.

The group also contends that the City Council violated Occupy Maine’s constitutional rights when it denied the group a permit earlier this month. Occupy Maine argued that the city could have granted waivers or variances as it does to commercial interests, but that the city’s denial was based on the group’s activities and message.

Branson said Occupy Maine is unusual in that it sought permission from the city and never denied that Portland had a right to regulate the group’s continuous assembly.

“We were invited here,” Branson said. “The city manager recognized this as First Amendment activity from the start.”

Jonathan Piper, a Portland-based First Amendment lawyer, said Occupy Maine have a stronger argument because it did try to work through the permitting system.

“It’s like, most municipalities have a parade permit. You can’t just have a mob run down the middle of the street. But if you say at 12 o’clock noon, to celebrate this or protest that, then the city would have to show good reason why you can’t be issued a permit,” Piper said.

The city has 21 days to respond and Occupy Maine will have a week to reply. A hearing could then be scheduled.

Nicole Clegg, a city spokeswoman, said the it was too early to respond to the Occupy Maine’s legal argument.

“The legal team’s all starting to review it,” she said, adding that the timing of the city’s response will depend on the complexity of Occupy Maine’s complaint.