Updated

The Texas division of the Sons of Confederate Veterans has filed a lawsuit in federal court arguing that the Department of Motor Vehicles infringed on its free speech rights by refusing to issue a specialty license plate featuring a Confederate flag, the Los Angeles Times reports.

The Columbia, Tenn.-based group, with 30,000 members, released a statement last week announcing the suit, which was filed in U.S. District Court in Austin.

"The First Amendment clearly protects controversial speech," the group said in a statement sent to The Times, noting that the same day the eight-member DMV board voted unanimously to reject the Confederate plate last month it approved a plate that "is offensive to Native Americans" because it honors the Buffalo Soldiers, an all-black cavalry that helped fight Native Americans in the 1800s.

"The board seeks to bar the Texas SCV from expressing their viewpoint while allowing all other groups to express their viewpoint. This type of restriction is exactly the type which the 1st Amendment is designed to erase," the statement said.

Texas officials turned down a Sons of Confederate Veterans' request for a specialty plate three years ago, citing rules that banned political or controversial plates. The rules changed two years ago, and the board has since approved all 89 proposed specialty designs.

"We said if we don't get the plates we're going to sue them," Marshall Davis, a spokesman for the group in Austin, told The Times. "There are other organizations that have had to sue their states to get their First Amendment rights, and this is the same thing."

Davis said his group was optimistic it would prevail because "a precedent has been set" in other states.

Nine other states have approved Sons of Confederate Veterans' specialty plates, but Virginia, Maryland and North Carolina only did so after the group sued. A similar suit is pending in Florida.

DMV officials told the Associated Press they had not yet seen the lawsuit.