The Redskins walk off the field after losing to the host Philadelphia Eagles on Sunday at Lincoln Financial Field. (Toni L. Sandys/The Washington Post)

The Native Americans fighting the Washington Redskins over trademark protections filed a motion in U.S. District Court in Alexandria on Monday, asking the court to toss the team’s lawsuit against them.

The motion argues that team owner Dan Snyder doesn’t have the legal right to sue the five Native Americans who won a key decision by the U.S. Patent and Trademark Office earlier this year. The patent office ruled that the name and logo are disparaging and canceled the team’s trademark registration.

The team sued last month, asserting that “Redskins” is not offensive and that the federal agency erred in stripping away six Redskins trademarks.

Snyder has promised never to change the team name, which he contends honors Native Americans. The team has cited polls that have shown that a majority of Native Americans or Americans do not find the team name offensive.

“On behalf of the club, we remain confident in our legal case and look forward to a hearing before the district court,” Bob Raskopf, the team’s attorney, said in a statement.

In their motion against the National Football League giant, the Native Americans argue that, based on federal law, they are not “parties in interest” who can be sued in a trademark case. The Native Americans — led by Amanda Blackhorse, a social worker and member of the Navajo Nation — have no legal or economic interest in wresting control of the Redskins trademark for themselves as a competing business might.

“They stand to gain nothing or lose nothing,” their attorneys’ motion says. “Although [the Native Americans] might be pleased or disappointed with the outcome of this case, that does not make them ‘parties in interest,’ ” as defined by federal trademark law.

Not only did the Redskins sue the wrong people, the motion says, but the team also filed its challenge to the trademark decision in a courthouse that lacks proper jurisdiction. The Redskins should have filed its case against the patent office in the U.S. Court of Appeals for the Federal Circuit in Washington, according to the motion, which was written by Jesse Witten and Jeffrey J. Lopez.

Since the team sued the Native Americans in the U.S. District Court in Alexandria, the lawsuit must be tossed because the Constitution requires judges at that level to take cases only when an actual “case or controversy” exists between two parties, the motion says.

The five Native Americans say in their motion that the “controversy” exists only between the team and the U.S. Patent and Trademark Office, which the Redskins accuse of violating its First Amendment and due process rights.

The Native Americans contend that the Redskins “apparently made a strategic decision” not to appeal in the U.S. Court of Appeals for the Federal Circuit, “presumably because that Court has already rejected [the team’s] Constitutional arguments.”

If a judge ultimately grants the Native American’s motion to dismiss, Snyder might risk being out of any more options to keep fighting for the federal trademark protections. Since the patent office’s Trademark Trial and Appeal Board’s ruling came down in June, he has exceeded the 60-day period given to appeal the decision.

Here's a look at the Redskins' logo and team imagery throughout the years. (Tom LeGro and Natalie Jennings/The Washington Post)

If the team loses, the patent and trademark office’s ruling will weaken the team’s ability in courts to fight against other businesses that copy or use the Redskins trademarks. But even then, the Redskins can still rely on trademark protection under federal common law.