PHOENIX - The Tohono O'odham Nation is asking a federal judge to void a new state law that allows Glendale to annex the property on which the tribe wants to build a casino.

Attorneys for the Southern Arizona tribe contend the measure, signed earlier this month by Gov. Jan Brewer, violates state and federal constitutional provisions. They also said it is in direct contravention of a 1986 federal law that specifically authorized the tribe to buy land and have it included in the reservation.

Aside from seeking to overturn the law, the tribe wants the court to block Glendale from annexing the property, a move that would thwart the planned casino.

The lawsuit is not a surprise. Tribal Chairman Ned Norris Jr. had written the governor last month, before she signed the measure, warning her that the issue would wind up in court.

But Brewer press aide Matthew Benson said the governor is not worried.

"The governor believes the law is constitutional and she's confident the state will prevail in court," he said.

At the heart of the fight is a plan by the tribe to erect a casino on land it purchased in 2003.

That purchase was specifically authorized by federal law in 1986 after a dam project flooded close to 10,000 acres of reservation land near Gila Bend. Congress said the O'odham could purchase replacement acreage anywhere in Maricopa, Pinal or Pima counties. And there was no mandate that it be adjacent to the existing reservation.

The law also allows the tribe to petition to have any newly acquired lands made part of the reservation - but only if the land is not within the limits of any city.

That reservation status is necessary before the tribe can operate a casino there.

A state judge subsequently ruled that part of the 135 acres the tribe bought at the edge of the city is within Glendale's limits. But that still left about 54 acres to build the facility.

State law generally requires the consent of a majority of landowners to annex any property. But this new law says any community in a county of at least 350,000 may annex any land it borders on three sides if the land's owner has petitioned the federal government to have it made part of a reservation.

Proponents made no secret that it was crafted so narrowly as to apply specifically to Glendale - and specifically to the O'odham parcel. And they admitted they rushed it through in hopes of having it take effect before a judge rules in another federal lawsuit challenging the right of the tribe to build a casino there.

Jonathan Jantzen, O'odham attorney general, pointed out the state constitution prohibits lawmakers from enacting special laws affecting a single person or entity. He said that, as far as he can tell, the only parcel that would be affected is the one owned by the tribe.